Vda Simplified Cad Drawing

Supersedes VDA 4953 Part 1: 1999-12 and Part 2: 2002-12

VDA

“CAD/CAM” Working Party “Drawing-free Product Documentation in Automotive Industry” Working Group

4953

Simplified CAD Drawing

This recommendation describes the transition from conventional to simplified drawings. It provides a means of transferring informational content which is traditionally contained in drawings to the 3D CAD model or to external files or databases. Product descriptions found in modern drawings are reduced to a minimum. The totality of the master data found in the drawings consisting of automotive-industry-typical product descriptions is divided into an industry-recommended master data sheet and company-defined master data. It describes how this information removed from the drawing can be standardised and structured in a master data sheet to enable clear access and data transfer. Comments are also included on the usability of suitable data formats, and recommendations on various applications are made using examples. The main purpose of this guideline is to ensure that text descriptions which are currently presented via the medium of drawings are made available to product data management systems as electronically processible content. Technical directives, test specifications, normative references and descriptions of technical revisions over the product life cycle are also dealt with. By defining the master data sheet, this recommendation has created a basic structure which will better enable the automotive industry to meet the constantly growing requirements with regard to statutory regulations and product liability in future through the use of product data management systems. Furthermore, it will be possible to minimise the extra input required for the parallel maintenance of product information in drawings and in the product data management system and to improve data consistency. The recommendation deals with the following subject areas: •

Structuring of product data in master data sheet, simplified drawing and 3D model

•

Minimum content of 3D CAD model, simplified drawing and master data sheet

•

Extent of dimensioning on simplified drawings.

•

Treatment of technical directives, specifications, normative references

•

Company-defined master data

•

Possibility of maintaining master data for several companies simultaneously

•

Descriptions of revisions

•

Dealing with multilingual master data

•

Conformity of master data sheet to STEP AP 214

•

Handling of existing standards and archiving

VDA “CAD/CAM” Working Party: Audi, Becker Group, Behr, BMW, Bosch, Brose, Continental, Continental Teves, DaimlerChrysler, Delphi Deutschland GmbH, Flachglas, Ford, Freudenberg, Hella, Iveco, Johnson Controls, Karmann, Keiper, Mahle Filtersysteme, Kostal, Krupp Bilstein, Küster, Lucas, MAN, Mannesmann- Sachs, Mannesmann- VDO, Opel, Pierburg, Porsche, Sekurit, Siemens, Volkswagen, Wabco, Webasto, ZF Friedrichshafen Published by: German Association of the Automotive Industry (VDA) Westendstrasse 61 Postfach 17 05 63 D-60079 Frankfurt / M., Germany Tel. +49 (0)69/97507-283 Fax +49 (0)69/97507-300

Copyright: Reproduction, in whole or in part, is only permitted with the prior approval of the publisher.

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1

Foreword _______________________________________________________ 3

2

Scope __________________________________________________________ 3

3

General _________________________________________________________ 3

4 Product presentation via 3D CAD model, simplified drawing and master data sheet ______________________________________________________________ 5 5

Minimum content and execution ____________________________________ 7 5.1

Execution of 3D CAD model __________________________________________ 7

5.2

Minimum content of master data sheet _________________________________ 8

5.3

Minimum content and execution of simplified CAD drawing _______________ 8

6

Definition of master data attributes to VDA 4953 _______________________ 9 6.1

Definition of generally applicable attributes _____________________________ 9

6.2

Definition of company-defined attributes ______________________________ 15

7

Structure of the master data sheet _________________________________ 15 7.1

Content of the master data sheet _____________________________________ 16

7.2

Multiple occurrences of keywords ____________________________________ 17

7.3

Revision description _______________________________________________ 18

8

Use of master data sheet _________________________________________ 19 8.1

Output options and data exchange ___________________________________ 19

8.2

Handling of existing standards and archiving __________________________ 19

9

XML syntax of master data sheet to VDA 4953________________________ 20 9.1

Elements of an XML master data sheet ________________________________ 21

9.2

Examples of entries in XML file ______________________________________ 23

9.3

Revision descriptions in master data sheet ____________________________ 24

9.3.1 9.3.2 9.3.3

Description of revision of master data sheet ___________________________________24 Revisions of simplified drawing in master data sheet_____________________________25 Description of revision of 3D CAD model in master data sheet _____________________26

10

Example of drawing simplification in accordance with VDA 4953 ______ 27

11

Comparison of VDA 4953 XML format with STEP____________________ 37

12

Conclusion and prospects ______________________________________ 37

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1 Foreword Different versions of reduced or simplified drawing records are currently in everyday use in the industry. This recommendation describes the transition from conventional to simplified drawings taking account of the points listed. It provides a means of transferring informational content which is traditionally contained in drawings to the 3D CAD model or to external files or databases. PDM (product data management) systems are becoming increasingly popular in the industry. However, a wealth of information (e.g. texts) without any direct reference to geometry is still being managed in drawings and therefore entails a relatively large amount of work if it is to be transferred to other computer systems. It is recommended that organisational master data and design features relating to the part as a whole be moved to separate files, databases or product management systems, meaning they are no longer an integral part of the 3D model and drawing. The points listed in this guideline should be observed. The management of this product data in any PDM systems used and system-neutral data exchange are guaranteed as a result. If no PDM system is yet in use in the companies, switching to VDA 4953 is a suitable means of paving the way for the future introduction of a PDM system. The more complex the part geometry, the more beneficial a 3D CAD model is. Drawing geometry is derived solely from the 3D CAD model. This data has to be retrieved from the 3D model. All main and functional dimensions, dimensions with a stated tolerance and data with reference to part geometry are presented as hitherto in a drawing. This recommendation has been drawn up by the ‘Drawing-free Product Documentation in Automotive Industry’ working group of the VDA CAD/CAM working party.

2 Scope This recommendation applies where 3D CAD models are used for documenting parts from which drawings are derived and if text information, unlike in a conventional drawing, is removed, separately managed and exchanged in order to document parts. Parts within the meaning of this recommendation include individual parts and assemblies. This recommendation deals with drawings for production parts, not drawings describing tooling or production processes.

3 General By contrast with traditional technical drawings the simplified drawing alone does not fully describe the part. The product description in accordance with this recommendation consists of: •

3D CAD model

•

Simplified drawing according to VDA 4953

•

Master data sheet according to VDA 4953

The dimensioning in the simplified drawing should be “production- and testing-compliant”. NC planning systems now use the 3D CAD model as the basis for programming. Consequently, the fully dimensioned description of the part shape and design in the drawing is no longer appropriate. It is more or less impossible with free-form geometry.

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The simplified drawing, therefore, contains no general dimensioning of the geometry. On specific parts it is acceptable to deviate from this rule for the process chain with the agreement of all relevant departments. The simplified drawing now only contains the text information which is necessary to permit general understanding and identification of the part. All other text information is managed in a master data sheet. The term “master data” is used to mean all non-geometric data which relates to the overall part and is of a design or organisational nature. The master data sheet can be managed in a separate file or database system and viewed using a suitable viewer. It refers to the relevant 3D CAD model and the associated simplified drawing. It can contain the revision description and complete revision history. If required, the relevant data can be output in hardcopy form. Since the master data sheet can be specified by version, all the documents forming part of the product description can be clearly identified at any time. It is possible to define companyspecific master data, manage master data multilingually and present it in parallel for different companies. The complete description of the part which is binding for release purposes requires the combination of the simplified drawing with the relevant three-dimensional data record (3D CAD model) and the master data sheet, see Fig. 3-1. The procedure described with a master data sheet can also be applied in principle without the presence of a 3D model.

Master data sheet

3D CAD model

Simplified

File/database

CAD drawing

• • • •

Viewing Data exchange Data processing Archiving

PDM system

Fig. 3-1: Presentation of product data by combining the simplified drawing with the relevant three-dimensional data record (3D CAD model) and the master data sheet

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4 Product presentation via 3D CAD model, simplified drawing and master data sheet Within the process chain from creation to completion the 3D CAD model is the guiding geometric description (digital master), while the master data sheet is the guiding description of non-geometric data. The simplified drawing retains the information with a direct reference to the part geometry (e.g. dimensions with a special tolerance or features which describe only partial areas of the part geometry). The 3D CAD model is modelled completely as a surface or solid model. It must be ensured that the master data sheet, the 3D CAD model and the simplified drawing can be exchanged, viewed and consistently maintained with regard to all revisions throughout the process chain. This includes the possibility of conversions. All valid drawing and release guidelines, standards and CAD standards must be observed in the creation, revision, documentation and release of the simplified drawing, the 3D CAD models and the master data sheet. Redundant information must be avoided. Where this is not possible, the information contained in the 3D CAD model, simplified drawing and master data sheet must be identical. In the case of a change of hardware or software it is essential to ensure that the existing product data is still fully readable and can be analysed. Archiving must comply with the requirements of DIN 6789-6. The table below, based on DIN 6789, shows the changes compared to conventional drawings with respect to the characteristics of the part to be described (Table 4-1). It is possible to exchange this data – also separately from the CAD model – irrespective of the system used via the VDA 4953 XML format (see section 9).

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Terms from DIN 6789, Part 2 Part characteristics Form/shape

Description of geometry, views, sections, details

Position

Position of items

Dimensions

Dimension line, subsidiary line, dimension figure Geometric dimensioning and tolerancing General tolerances Company, copyright notice, document number, release status, date of issue, created by, checked by, data processing key, ID number, name, title

Tolerances

Organisational master data

Design master data relating to overall part

Revisions: identification on geometry Revisions: description Notes and instructions relating to part

Characteristics, notes and technical directives relating to geometry

Unit, weight, quantity, material, hardness, tempering, material treatment, semifinished product, surface treatment, coating, aftertreatment, surface finish Revision index

Revision index Technical specification, supply specification, technical directives, company standard Material, hardness, tempering, material treatment, surface treatment, coating, aftertreatment, surface finish, technical specification, company standard, parts identification, technical directives

Conventional drawing

VDA 4953 Simplified drawing, 3D CAD model and master data sheet --------------------------------------------------------> Views, sections, details (possibly Fully modelled in 3D CAD model (solid or obtained from 3D CAD model) surface model), dimensionally accurate to nominal dimensions. 3D CAD model is guiding geometric description.

Presentation of assembly drawing using projected views, sections, details (if nec., in co-ordinate system / vehicle grid) Part completely described using dimensioned presentations in views, sections, details Information using projected views, sections, details, if nec. dimension figure In title block In title block / frame of drawing

Views, sections, details derived solely from 3D CAD model. Transparent mode, if appropriate. Fixed view layout. Uses increasingly spatial views. = conventional drawing 3D assembly drawing, DMU In drawing: main/functional dimensions and dimensions which have to be specifically tolerated. = conventional drawing

Separate file/database* Separate file/database* Note referring to current 3D data record. Note “Simplified drawing to VDA 4953”

In title block / frame of drawing

Separate file/database*

Revision index on geometry in views, sections, details

= conventional drawing; also indication of 3D co-ordinates

Revision table in title block or separately, Separate file/database* reference via revision index As text in drawing Separate file/database*

As text with reference to geometry in projected views, sections, details

= conventional drawing

Table 4-1: Overview of drawing simplification in accordance with VDA 4953 * ) Note: “Separate file/database“ also includes the option for storing this data in the CAD model or in a PDM system.

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5 Minimum content and execution 5.1 Execution of 3D CAD model Models are to be created in the form of solid or surface models. In general, wire frame models are not a suitable means of providing complete documentation. VDA guideline 4955 must be met in respect of data quality. It is possible to reduce the geometry of required connecting or assembly faces to the mating surfaces. The part is presented complete and dimensionally accurate (nominal dimensions). That means all shaped elements such as angled surfaces, fillets, holes and ribs must be shown. Threads and teeth are not produced in the model but are shown in the simplified drawing. In the case of thin-walled parts of even thickness, e.g. parts made of sheet metal, it is sufficient to show one side as a surface model. In this case, the material side must be identified in the 3D CAD model, e.g. by showing a line with length = 100 x material thickness perpendicular to the surface (Fig. 5-1) or by an offset curve at a distance from the surface equivalent to the material thickness (Fig. 5-2).

Fig. 5-1: Line of length = 100 x material thickness

Fig. 5-2: Offset curve

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5.2 Minimum content of master data sheet The master data sheet must contain at least the following data. The keywords are described in paragraph 6.1 below: •

Owner (company name) / company: OWNER

•

ID number of master data sheet: MASTER_DATA_SHEET_ID_NUMBER

•

Revision level of master data sheet: MASTER_DATA_SHEET_REVISION _LEVEL

•

Created by: MASTER_DATA_SHEET_CREATED_BY

•

Date of issue: MASTER_DATA_SHEET_DATE_OF_ISSUE

•

Responsible person: MASTER_DATA_ SHEET_APPROVED_BY

•

Part number: PART_NUMBER

•

Name / part: PART_NAME

•

Part revision level: PART_REVISION_LEVEL

•

Tolerancing principle: TOLERANCING_PRINCIPLE

•

Unit system used: UNIT_SYSTEM

•

ID number of 3D CAD model MODEL_3D_ID_NUMBER

•

Revision level of 3D CAD model MODEL_3D_REVISION_LEVEL

•

ID number of simplified drawing: SIMPLIFIED_DRAWING_ID_NUMBER

•

Revision level of simplified drawing: SIMPLIFIED_DRAWING_REVISION_LEVEL

•

Language: LANGUAGE, in event of multilingual sheet

5.3 Minimum content and execution of simplified CAD drawing The simplified drawing to VDA 4953 must contain at least the following data, where this is required to enable the part to be understood: •

One view, isometric if necessary

•

Further projected views and sections, if required

•

Drawing frame with title block

•

Main dimensions, functional dimensions and toleranced dimensions

•

Geometric dimensioning and tolerancing

•

Owner (company name) / company

•

Date of issue

•

ID number of simplified drawing

•

ID number of master data sheet or reference to master data sheet with same number

•

Note “Simplified drawing according to VDA 4953” (translated, if necessary)

•

Revision level of simplified drawing

The simplified drawing must be produced in accordance with the following requirements: •

The geometry of the drawing is completely derived from the 3D CAD model.

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•

The drawing is prepared in accordance with ISO standards.

•

The simplified drawing has a drawing frame and a title block which is reduced when compared with a conventional drawing.

•

The content of the drawing shall allow an assessment in principle of the part by showing toleranced main and functional dimensions and, if appropriate, the position of the part in the system of co-ordinates.

•

Apart from the above, only those dimensions should be marked which are a specific tolerance requirement for the part.

•

Stepped sections should be avoided (section drawings only in one plane).

•

All geometric revisions shall be carried out in the 3D CAD model.

6 Definition of master data attributes according to VDA 4953 6.1 Definition of generally applicable attributes Table 6-1 below contains the definitions of the attributes which could be found as texts in drawings to date and which will in future be shown in the master data sheet and may be exchanged. DIN 6789-2, ISO 7200-1 and 2 standards and company-specific documents of collaborating companies were used to select the attributes. Unique English keywords are assigned to the attributes in Table 6-1. The importance of machine readability was stressed. Table 6-1 has been divided into the following sections to ensure clarity: •

Organisational attributes

•

Part attributes

•

3D CAD model attributes

•

Simplified drawing attributes

•

Revision order attributes

The ability to identify the part, 3D CAD model, master data sheet and drawing by means of different ID numbers and revision levels ensures that documents which belong together can be managed irrespective of the numbering and data storage systems. The “Title block” and “Master data sheet” columns describe where the master data is displayed. These columns show whether the entries in the master record sheet or the title block of the simplified drawing are •

mandatory (m) or

•

optional (op) or

•

not (- = not) listed

The “Occurrences per company” column contains information on whether an attribute within a master data sheet relating to a company can occur •

once (1)

•

never (0) or

•

any number of times (n)

(see paragraph 7.2). Irrespective of this, even an attribute which may only occur once in the master data sheet may occur translated into multiple languages. __________________________________________________________________________ Copyright VDA

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Keyword

Title block

Master data sheet

Bold = attributes which are mandatory in the master data sheet or simplified drawing

Definition

Multilingual

Attribute

Occurrences per company

The “Multilingual” column marks the attributes whose content may be multilingual.

Organisational attributes Owner (company name) / company

OWNER

m

m

1

-

Name of organisation which owns document (simplified drawing, 3D CAD model and master data sheet) Also indicates what is binding in event of entries for several companies in cases of doubt

Copyright notice

COPYRIGHT

op

op

1

op

Description of type of copyright protection.

Project

PROJECT

-

op

1

op

Project identification in accordance with owner’s specification

Work order number

WORK_ORDER_NUMBER

-

op

1

-

Number of design order in accordance with owner’s specification

Language

LANGUAGE

-

m

1

-

Mandatory attribute with multilingual content in master data sheet. Identifies binding language in cases of doubt.

ID number of master data sheet

MASTER_DATA_SHEET_ ID_NUMBER

m *)

m

1

-

Clear identification of master data sheet in accordance with owner’s coding system *) Only mandatory in text block if different ID numbers are used for simplified drawing and master data sheet

Revision level of master data sheet

MASTER_DATA_SHEET_ REVISION_LEVEL

op

m

1

-

Clear identification of revision level of master data sheet in accordance with owner’s coding system

Created by

MASTER_DATA_SHEET_ CREATED_BY

-

m

1

-

Name of person who created master data sheet (must be specified for each company)

Date of issue

MASTER_DATA_SHEET_ DATE_OF_ISSUE

-

m

1

-

Date on which master data sheet was issued (must be specified for each company). It is recommended that date on which product data was first defined in master data sheet be specified.

Replaces

MASTER_DATA_SHEET_ REPLACES

-

op

1

-

ID number of master data sheet replaced by this one (in accordance with owner’s specification)

Replaced by

MASTER_DATA_SHEET_ REPLACED_BY

-

op

1

-

ID number of master data sheet by which this one was replaced (in accordance with owner’s specification)

Department

MASTER_DATA_SHEET_ CREATED_BY_DEPARTMENT

-

op

1

-

Department in which master data sheet was created

Responsible person

MASTER_DATA_SHEET_ APPROVED_BY

-

m

1

-

Name of person responsible for content and updating of master data sheet

Responsible

MASTER_DATA_SHEET_ APPROVED_BY_DEPARTMENT

-

op

1

-

Name of department responsible for content and updating of master data sheet

department/department in control

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Keyword

Title block

Master data sheet

Bold = attributes which are mandatory in the master data sheet or simplified drawing

Definition

Multilingual

Attribute

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Occurrences per company

VDA Recommendation 4953

Release status

MASTER_DATA_SHEET_ RELEASED_STATUS

-

op

1

op

Release status in conjunction with (revision) level of specified master data sheet

Released by

MASTER_DATA_SHEET_ RELEASED_BY

-

op

1

-

Name of person releasing master data sheet

Release date

MASTER_DATA_SHEET_ RELEASED_DATE

-

op

1

-

Date on which master data sheet was released

Checked by

MASTER_DATA_SHEET_ CHECKED_BY

-

op

1

-

Name of person(s) who checked content and updating of master data sheet (must be specified for each company)

Part number

PART_NUMBER

op

m

1

-

Clear identification of part in accordance with owner’s coding system

Name / part

PART_NAME

op

m

1

op

Part name in one or more words

Part revision level

PART_REVISION_LEVEL

op

m

1

-

Clear identification of revision level of physical part in accordance with owner’s coding system

Tolerancing principle

TOLERANCING_PRINCIPLE

-

m

1

-

Principle of relationship between dimensional tolerances (linear and angular dimensions) and geometric dimensioning and tolerancing

General tolerances

GENERAL_TOLERANCES

-

op

1

-

Value of general tolerances which have to be used if no tolerances are specified with dimensions

Treatment

TREATMENT

-

op

n

op

“Treatment” covers heat treatment, paintwork, etching, tempering, hardness, material treatment, surface treatment, colour, pattern, coating, aftertreatment etc.

Surface protection

SURFACE_PROTECTION

-

op

1

op

Identification of surface protection used

Calculated weight (g)

WEIGHT_CALCULATED

-

op

1

-

Value and unit of weight (mass) of object shown, determined by calculating volume, multiplied by density of material of which object is made

Measured production weight (g)

WEIGHT_FINAL

-

op

1

-

Value and unit of weight (mass) of object shown for production status, determined in weighing trials

Measured prototype weight (g)

WEIGHT_PROTOTYPE

-

op

1

-

Weight determined in weighing trials of prototype parts (not yet production status)

Semi-finished product

SEMI_FINISHED_PRODUCT

-

op

1

op

Semi-finished product specification. Semifinished products are: rolled, forged, drawn, pressed or otherwise manufactured profile sections, bars, rods, tubes, wires, sheets, plates, panels, coils, strips, foils and similar product forms

Unit system used

UNIT_SYSTEM

-

m

1

-

Indication of unit system applicable to design, e.g. SI

Surface

PAINT_SURFACE

-

op

1

-

Size (figure and unit) of surface area of part shown intended to be painted (Endof-Life Vehicles Order).

Part attributes

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Keyword

Title block

Master data sheet

Bold = attributes which are mandatory in the master data sheet or simplified drawing

Definition

Multilingual

Attribute

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Occurrences per company

VDA Recommendation 4953

Technical directive

TECHNICAL_DIRECTIVE

-

op

n

op

Technical directive relating to handling, production, assembly, testing, transport, use etc. of product

Technical specification

TECHNICAL_SPECIFICATION

-

op

n

op

Details of specified product properties e.g. embodiments, test properties, permitted and non-permitted product constituents etc.

Reference

REFERENCE

-

op

n

-

Reference to other standards/specifications, e.g. ISO/DIN/ANSI standards, company standards, test requirements etc.

Material

MATERIAL

-

op

1

op

Identification of material from which object shown is manufactured

Material number

ID_NUMBER_MATERIAL

-

op

1

-

ID number of stated material

General surface roughness

SURFACE_ROUGHNESS

op

op

1

op

Values of surface roughness if no other values are stated

*)

*)

*) Character set for presenting roughness symbols unavailable at present! Instead, use word-based description, e.g. Rz 10, no machining permissible. Consequently, multilingual also

3D CAD model attributes ID number of 3D CAD model

MODEL_3D_ID_NUMBER

op

M

1

-

Clear identification of 3D CAD model in accordance with owner’s coding system

Revision level of 3D CAD model

MODEL_3D_REVISION_LEVEL

op

M

1

-

Clear identification of revision level of 3D CAD model in accordance with owner’s coding system

Created by

MODEL_3D_CREATED_BY

-

op

1

-

Name of person who created 3D CAD model (must be specified for each company)

Date of issue

MODEL_3D_DATE_OF_ISSUE

-

op

1

-

Date on which 3D CAD model was issued (must be specified for each company).

Replaces

MODEL_3D_REPLACES

-

op

1

-

ID number of 3D CAD model replaced by this one (in accordance with owner’s specification)

Replaced by

MODEL_3D_REPLACED_BY

-

op

1

-

ID number of 3D CAD model by which this one was replaced (in accordance with owner’s specification)

Department

MODEL_3D_ CREATED_BY_DEPARTMENT

-

op

1

-

Department in which 3D CAD model was created

Responsible person

MODEL_3D_APPROVED_BY

-

op

1

-

Name of person responsible for content and updating of 3D CAD model

Responsible

MODEL_3D_ APPROVED_BY_DEPARTMENT

-

op

1

-

Name of department responsible for content and updating of 3D CAD model

Release status

MODEL_3D_RELEASED_STATUS

-

op

1

op

Release status in conjunction with (revision) level of specified 3D CAD model

Released by

MODEL_3D_RELEASED_BY

-

op

1

-

Name of person releasing 3D CAD model

department/department in control

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Keyword

Title block

Master data sheet

Bold = attributes which are mandatory in the master data sheet or simplified drawing

Definition

Multilingual

Attribute

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Occurrences per company

VDA Recommendation 4953

Release date

MODEL_3D_RELEASED_DATE

-

op

1

-

Date on which 3D CAD model was released

Checked by

MODEL_3D_CHECKED_BY

-

op

1

-

Name of person(s) who checked content and updating of 3D CAD model (must be specified for each company)

Name and version of CAD system

MODEL_3D_CAD_SYSTEM

-

op

1

-

Details of (CAD) system with relevant version used to create 3D CAD model

Simplified drawing attributes ID number of simplified drawing

SIMPLIFIED_DRAWING_ ID_NUMBER

m

m

1

-

Clear identification of simplified drawing in accordance with owner’s coding system

Revision level of simplified drawing

SIMPLIFIED_DRAWING_ REVISION_LEVEL

m

m

1

-

Clear identification of revision level of simplified drawing in accordance with owner’s coding system

Created by

SIMPLIFIED_DRAWING_ CREATED_BY

op

op

1

-

Name of person who created simplified drawing (must be specified for each company)

Date of issue

SIMPLIFIED_DRAWING_ DATE_OF_ISSUE

m

op

1

-

Date on which simplified drawing was issued (must be specified for each company)

Replaces

SIMPLIFIED_DRAWING_ REPLACES

-

op

1

-

ID number of simplified drawing (e.g. old, conventional drawing) which was replaced by this one (in accordance with owner’s specification)

Replaced by

SIMPLIFIED_DRAWING_ REPLACED_BY

-

op

1

-

ID number of simplified drawing by which this one was replaced (in accordance with owner’s specification)

Department

SIMPLIFIED_DRAWING_ CREATED_BY_DEPARTMENT

-

op

1

-

Department in which simplified drawing was created

Responsible person

SIMPLIFIED_DRAWING_ APPROVED_BY

op

op

1

-

Name of person responsible for content and updating of simplified drawing

Responsible

SIMPLIFIED_DRAWING_ APPROVED_BY_DEPARTMENT

-

op

1

-

Name of department responsible for content and updating of simplified drawing

Release status

SIMPLIFIED_DRAWING_ RELEASED_STATUS

op

op

1

op

Release status in conjunction with (revision) level of specified simplified drawing

Released by

SIMPLIFIED_DRAWING_ REPLACED_BY

-

op

1

-

Name of person releasing simplified drawing

Release date

SIMPLIFIED_DRAWING_ RELEASED_DATE

-

op

1

-

Date on which simplified drawing was released

Checked by

SIMPLIFIED_DRAWING_ CHECKED_BY

-

op

1

-

Name of person(s) who checked content and updating of simplified drawing (must be specified for each company)

Name and version of CAD system

SIMPLIFIED_DRAWING_ CAD_SYSTEM

-

op

1

-

Details of (CAD) system with relevant version used to create simplified drawing

Number of sheets

SIMPLIFIED_DRAWING_ NUMBER_OF_SHEETS

op

op

1

-

Total number of sheets of which simplified drawing is composed

op

-

0

-

Identification of sheet in drawing

department/department in control

Sheet number

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Keyword

Title block

Master data sheet

Bold = attributes which are mandatory in the master data sheet or simplified drawing

Definition

Multilingual

Attribute

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Occurrences per company

VDA Recommendation 4953

Scale

m

-

0

-

Ratio of linear dimensions of object shown to object’s actual linear dimensions. DIN ISO 5455

Projection method

op

-

0

-

Rules for deriving two-dimensional view of three-dimensional object

Drawing format

op

-

0

-

Format of relevant sheet size

Revision order attributes Revision of master data sheet

MASTER_DATA_SHEET_REVISION

-

op

n

op

Describes revision of organisational attributes or part attributes

Revision of 3D CAD model

MODEL_3D_REVISION

-

op

n

op

Describes revision of 3D CAD model

Revision of simplified drawing

SIMPLIFIED_DRAWING_REVISION

-

op

n

op

Describes revision of simplified drawing

Table 6-1: Definition and use of master data attributes and their keywords

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6.2 Definition of company-defined attributes It is desirable, though not essential, for the companies to adopt the attributes defined in Table 6-1 “as is”. What was considered more important, however, was to convert the attributes used to date within the companies to keywords in accordance with VDA 4953, provided conversion is possible while retaining the meaning. This conversion is carried out before the master data sheet is forwarded to a development partner. Conversely, the keywords contained in a master data sheet are converted back into in-house attributes on receipt of the sheet. Conversion tables are established at the participating companies which specify which in-house attributes are converted into which keywords to VDA 4953 and vice versa (Fig. 6-1).

Company A

A´s inhouse terms

conversion into keywords according to VDA 4953

Company B

Master data sheet according VDA 4953

A´s conversion table

conversion into B´s inhouse terms

B´s inhouse terms

B´s conversion table

Fig. 6-1: Conversion of VDA 4953 attributes to in-house attributes If it is not possible to convert an in-house attribute and retain the meaning, this can be listed in the master data sheet as a company-defined keyword. The originator must ensure that the meaning of the keyword is defined in accordance with Table 6-1. Keywords for companydefined attributes start with an underscore “_”. English keywords should be assigned to company-defined attributes. Companies exchanging a master data sheet should agree whether and how •

company-defined keywords

•

translations of content and

•

optional VDA 4953 keywords which are only used in one of the companies involved

should be further processed and returned, if appropriate. If two in-house terms should in theory be converted into the same VDA attribute, it is recommended that company-defined keywords be used here (e.g. to distinguish heat treatment from paintwork). If mandatory entries are not available at an early stage of the development process, this can be indicated in the master data sheet by using a “-” (dash) in the “Content” field (see paragraph 7.1).

7 Structure of the master data sheet This section describes the content structure of a master data sheet. This is not a statement of the actual structure of a master data sheet in a specified data format. __________________________________________________________________________ Copyright VDA

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The master data sheet contains the master data of a design which is independent of geometry. Account is taken of the procedures which are carried out within companies: •

Copying copyrighted drawing content from development partners unchanged into their own drawing frame

•

Writing multilingual drawing content

•

Using company-defined attributes

•

Maintaining one drawing for several customers

7.1 Content of the master data sheet Each of these master data items with the exception of the revision descriptions is listed in the master data sheet with •

Keyword

•

Name (company)

•

ID

•

Language

•

Content

The keyword identifies which general attribute from Table 6-1 or which company-defined attribute (see paragraph 6.2) is involved. Company-defined keywords (see paragraph 7.3) must be identified with an underscore “_”. The name contains the name of the company responsible for the content. It must be entered for each keyword used. If a keyword has multiple entries with different content for different companies, e.g. ID numbers for suppliers and customers, the respective company name must be entered in the Name field. In the case of company-defined keywords the originator of the keyword should be entered under Name. The owner specifies how the entry under Name is formed. The ID is used to number all master data entries. In the case of a multilingual sheet, the same content has the same ID in all the languages. This enables master data for different companies to be maintained multilingually in parallel. The language code in accordance with DIN 2335 (corresponding to ISO 639) is entered under Language. This indicates the language in which the entry under ‘Content’ was written. Examples: de

German

en

English

es

Spanish

fr

French

Table 7-1 : Language codes The master data values are entered under Content. It is assumed that there is no limit to the length of the entries in ‘Content’. An example of a possible structure for a master data sheet in tabular form is shown below:

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Keyword

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Name

ID

Language

Content

Table 7-2 : Tabular form of the master data sheet

7.2 Multiple occurrences of keywords The attribute ‘Owner’ (keyword ‘OWNER’) may only occur once in a master data sheet. In the case of the following attributes or keywords multiple entries (distinguished via ‘ID’) may be made for each company (distinguished via ‘Name’) within a master data sheet: •

Treatment (TREATMENT)

•

Technical directive (TECHNICAL_DIRECTIVE)

•

Technical specification (TECHNICAL_SPECIFICATION)

•

Reference (REFERENCE)

All attributes are numbered serially via the ID. Attributes which describe information for different companies or in different languages under the same keyword have the same ID. This ensures that attributes which belong together for a number of companies and in a number of languages can be identified. The content of the attribute assigned to the owner is binding in the event of any doubt. Each of the other attributes defined in Table 6-1 may occur once in each language (distinguished via ‘Language’) for each company (distinguished via ‘Name’) within a master data sheet. The following are the attributes which are translated into multiple languages: •

Copyright notice (COPYRIGHT)

•

Treatment (TREATMENT)

•

Surface protection (SURFACE_PROTECTION)

•

Technical directive (TECHNICAL_DIRECTIVE)

•

Technical specification (TECHNICAL_SPECIFICATION)

•

Release status (MASTER_DATA_SHEET_RELEASED_STATUS)

•

Release status (MODEL_3D_RELEASED_STATUS)

•

Release status (SIMPLIFIED_DRAWING_RELEASED_STATUS)

•

Project (PROJECT)

•

Part name (PART_NAME)

•

Semi-finished product (SEMI_FINISHED_PRODUCT)

•

Material (MATERIAL)

•

General surface roughness (SURFACE_ROUGHNESS)

•

Revision text

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7.3 Revision description Revisions are listed in the master data sheet with •

Keyword

•

Name

•

ID

•

Order number of revision (number of design order for completed revision)

•

Date of revision order (date on which revision order was issued)

•

Revision level

•

Position (identification of link between revision text and position of revision in master data sheet, simplified drawing or 3D

(revision level of master data sheet, simplified drawing or 3D CAD model to which revision text relates, in accordance with owner’s definition)

CAD model)

•

Revised by (name of person carrying out revision)

•

Revision date (date on which revision was made)

•

Language (language in which revision text was written)

•

Revision text (brief description of revision)

Keywords for revisions should be entered in accordance with the definition in Table 6-1. The keyword is •

MASTER_DATA_SHEET_REVISION

•

MODEL_3D_REVISION

•

SIMPLIFIED_DRAWING_REVISION

for revisions of organisational attributes or part attributes

for revisions of the 3D CAD model and for revisions of the simplified drawing

Multiple revision-related keywords may be used for a company within a master data sheet. The revision text is input under Revision text. It is assumed that there is no limit to the length of the entries in ‘Text’.

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8 Use of master data sheet 8.1 Output options and data exchange The master data sheet can be output in the following formats: •

XML (recommended by VDA 4953 working group, see section 9)

•

STEP AP 214 (see section 11)

The appropriate standardised methods are used for exchanging files (e.g. ENGDAT).

8.2 Handling of existing standards and archiving •

The relevant standards for the documentation of product data in the companies should continue to be used, and the statutory international specifications relating to this should also be observed, see section 4.

•

The information contained in section 3 should be noted. The establishment of a level which cannot be falsified and the joint archiving of the 3D CAD data, simplified drawing and master data sheet must be ensured.

•

Careful handling of the attributes to permit identification of documents which belong together must be ensured.

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9 XML syntax of master data sheet to VDA 4953 This section describes how a master data sheet to VDA 4953 can be handled as an XML file. The XML format is recommended because of the following features: •

The XML format is an easy-to-understand, structured format.

•

It is permanently archivable because XML is a readable format (ASCII/UNICODE).

•

It can be reformatted or converted to other formats, e.g. HTML, EXCEL/CSV, TEXT and STEP, with relatively little effort.

•

It can be printed out directly or generated as a PDF file.

•

Mapping in a different XML syntax is straightforward.

•

The format described here can be expanded at will because no keyword-specific XML tags1 have been defined. Expandable for VDA and company terms.

•

Suitable for holding information for several companies on the same part.

•

Multilingual content can be shown within the title blocks.

•

The revision history of the master data sheet, simplified drawing and 3D CAD model can be displayed.

•

Uniform system for master data content and revisions

•

Company-specific information relating to the same subject is collated in an block.

•

There are many ways of generating XML files (e.g. editors, database output, browsers). See also Fig. 10-6.

The XML syntax for creating the master data sheet is shown in Fig. 9-1. Application examples are discussed below. The first step is to mark the version of the master data attributes in accordance with VDA 4953. Then the attributes are defined in blocks. The company name and the content, with the latter in multiple languages, if necessary, are entered for each block. The revision order attributes can be placed before the content.

1

Tags are the XML elements notated in angle brackets

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1…k

1…j

1…i

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text containing the content […] = optional * = only if key = „XXX_Revision“ * * = only for company-defined keywords

Fig. 9-1: XML syntax to create the master data sheet Note: “XXX_REVISION” covers “SIMPLIFIED_DRAWING_REVISION”.

“MASTER_DATA_SHEET_REVISION”,

“MODEL_3D_REVISION”

and

9.1 Elements of an XML master data sheet Table 9-1 explains the elements of an XML master data sheet to VDA 4953.

Start of the file, XML processing instruction



XML root element for VDA 4953 files

Attributes of

version

Mandatory Contains the version of the VDA 4953 XML definition. In this case version=“1.0“.



Start of an attribute in the master data sheet Repetitions within a section from to are possible for each keyword (name) used.

Attributes of

id

Mandatory A serial number is entered under id to which reference can be made in the event of revisions. The id is retained when revisions are made to the content.

key

Mandatory The keyword identifies the attribute involved. Please refer to Table 6-1 for details of the keywords defined in VDA 4953. Company-defined keywords (see para. 6.2) should be indicated with an underscore “_”. An attribute entry must start with a letter or underscore (_), and the subsequent characters may consist of letters, numbers, underscores, dots or dashes, but not spaces.

Defined

Mandatory for company-specific keywords In the case of a company-specific keyword (starts with “_”) contains the name of the defining company. The owner specifies what text is entered under ‘defined’. An attribute entry must start with a letter or underscore (_), and the subsequent characters may consist of letters, numbers, underscores, dots or dashes, but not spaces.



Start of the content for a company Repetitions within a section from to are possible for each company (name) used. This enables master data for different companies to be maintained in parallel. Only entries describing the same content in different languages may be made within a block.

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Attributes of

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name

Mandatory “name” contains the name of the company responsible for the content. The company must be entered for each keyword used. If a keyword has multiple entries with different content for different companies, e.g. ID numbers for suppliers and customers, the respective company name must be entered in the “name” field. The owner specifies what text is entered as the name. The content of the attribute assigned to the owner is binding in the event of any doubt. An attribute entry must start with a letter or underscore (_), and the subsequent characters may consist of letters, numbers, underscores, dots or dashes, but not spaces.



Start of a content text Repetitions within a section from to are possible for each language (lang) used.

Attributes of

lang

Indicates the language in which the content is written. Language codes in accordance with ISO 639. Examples: de = German en = English es = Spanish fr = French Optional. If no entry is present, the language of the content text is assumed to be as in the entry under the keyword “LANGUAGE”.

workorder

Number of the design/revision order Optional. Is only used for key=“XXX_REVISION”.

wo_date

Date on which revision order was issued Optional. Is only used for key=“XXX_REVISION”.

rev_level

1

Date on which revision was made Optional. Is only used for key=“XXX_REVISION”.

Content text

1

Name of person carrying out revision Optional. Is only used for key=“XXX_REVISION”.

rev_date

1

Identification of link between revision text and position of revision in drawing and/or 3D CAD model. If revisions are made to the master data sheet, ‘position’ can contain the ATTR-id to which the revision relates. Optional. Is only used for key=“XXX_REVISION”.

person

1

Revision level of master data sheet, simplified drawing or 3D CAD model to which revision text relates (in accordance with owner’s definition) Optional. Is only used for key=“XXX_REVISION”.

position

1

1

Content text The master data values are entered here. It is assumed that there is no limit to the length of the entries in ‘Content’.



End of a content text



End of the content for a company



End of an attribute



End of the file

Table 9-1: Elements of an XML master data sheet to VDA 4953

1

See note under Fig. 9-1

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9.2 Examples of entries in XML file Table 9-2 contains a few examples of entries in an XML file to VDA 4953. Section 10 contains a detailed example. Example

Explanation



The GOODCAR AG company is the owner of the document.

GOODCAR AG Germany

The part number of the part described in this document is

XY1.522.044.00

XY1.522.044.00 at GOODCAR_AG



and



ZY1.555.001 at JEWELPARTS_GMBH

ZY1.555.001 Traeger fuer Verlaengerung

The name of the part described in the document is as follows at GOODCAR_AG German: Traeger fuer Verlaengerung, English: AS Extension

AS Extension

GOODCAR_AG uses the company-defined attribute “_AUX_PART_NAME”.

Sitzkissen

The content is described in German and English.

Seat cushion

Table 9-2: Examples of entries in the XML file

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9.3 Revision descriptions in master data sheet There are various ways of carrying out and combining the description of revisions in accordance with the XML syntax presented, some of which are shown below as examples. The methods to be used are specified separately by each company.

9.3.1 Description of revision of master data sheet In this method it is possible to list the entire revision history of the master data sheet in the master data sheet. (1) In the event of revisions to content in the master data sheet the previous content is replaced by the new content. (2) An block describing the revision is inserted. (3) The revision order (workorder), person making the revision (person) and the revision reference can optionally be added to the tag. (4) The revision date (rev_date) must be inserted in the tag. (5) The master data sheet revision level (MASTER_DATA_SHEET_REVISION_LEVEL) is increased. Table 9-3 shows examples. Before revision

1 0.141 Kg

After revision



(5)

2

(1)

0.135 Kg

(2)



(3),(4)

Calculated weight revised, was 0.141 kg

Table 9-3: Description of revision of the master data sheet (example)

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9.3.2 Revisions of simplified drawing in master data sheet All revisions of the drawing are described in the master data sheet. The revision level of the drawing (1) and the (2) master data sheet must be described in the master data sheet. (3) An block describing the revision is inserted. The revision order (workorder) (4), position (5) and the person making the revision (person) (6) can optionally be added to the tag. (7) The revision date (rev_date) must be inserted in the tag. Table 9-4 shows examples. Before revision

1

1

After revision



(2)

2

(1)

2

(3)



(4),(5),(6),(7)

View Z added

Table 9-4: Description of revision of simplified drawing (example)

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9.3.3 Description of revision of 3D CAD model in master data sheet

If all the revisions of the 3D CAD model are described in the master data sheet, the procedure is analogous to the description of revisions of the simplified drawing. Table 9-5 shows examples. Before revision

1

1

After revision

2

2

Hole added

Table 9-5: Description of revision of 3D model (example)

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10 Example of drawing simplification in accordance with VDA 4953 The notes and simplifications proposed in this recommendation are presented below taking the example of an “AS Extension Seat Cushion”. The drawing shown in Fig. 10-1 contains a wealth of data in text form. e.g. a comprehensive title block, details of weight, surface roughness, free size tolerances, material, check notes and company-specific details. Fig. 10-2 shows enlargements of the title block and revision field. In the simplified drawing to VDA 4953, Fig. 10-3, these details have been removed. The title block now only contains the minimum content, as explained in para. 5.2 (shown in enlarged form in Fig. 10-4). Since the ID numbers for the drawing and the master data sheet are identical in the example, the title block merely contains a number, termed “Basic No.” by m/s XY. The remaining details in the text block are optional (scale, projection method, drawing document size and sheet number). Fig. 10-5 shows the master data sheet which belongs to the example as an XML file. In this the master data is listed with its respective keywords, in accordance with the definition from section 6 and with content in accordance with para. 7.1. How the user sees the master data sheet depends on his table editor. It is recommended, as described in para. 6.2, that appropriate conversion tables and viewing filters be set which show the user the master data with the terms and in the language standardised in the respective company. Fig. 10-6 shows an option for outputting a printable version of a master data sheet. This route is intended as an exception for departments which are not given computer-assisted access to the master data sheet.

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Fig. 10-1: Conventional drawing __________________________________________________________________________ Copyright VDA

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Fig. 10-2: Conventional drawing (enlargement of detail)

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Fig. 10-3: Simplified drawing to VDA 4953 __________________________________________________________________________ Copyright VDA

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Fig. 10-4: Simplified drawing to VDA 4953 (enlargement of detail) Master data sheet as XML file: GOODCAR AG Bei Uebermittlung schutzfaehiger Informationen behaelt sich die GOODCAR AG alle Rechte fuer den Fall der Patenterteilung vor. Jede Verfuegungsbefugnis incl. Kopier- und Weitergaberecht bei uns. In case of communicating patentable information all rights arising in the event of a patent grant remain with GOODCAR AG. All rights of disposition particularly for copying or distributing are reserved. XY1.522.044.00 ZY1.555.001 Traeger fuer Verlaengerung AS Extension Sitzkissen Seat cushion XY1.522.044.00 ZY1.3D.555.001

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XY1.522.044.00 ZY1.ST001.555.001 XY1.522.044.00 ZY1.555.001.Z 003 003 003 003 Schulz 22.11.1999 Maier Mueller CATIA Version 4.2.4 CATIA Version 4.2.4

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de XYZ / 5501-234 Kabrio, Japan DIN 7167 SI DIN 47-11 ISO 2768 mk ABS 4711-01-A123 20 4712-02-B123 30 4712-03-C123

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45 OFL-1 0,135 Kg NR-101-K S ISO 1302 DIN 6784 NORM 101/102 NORM PVK-12 TLX 201-A Form nach CAD- Datensatz Allgemeine Wanddicke: 2,5 mm Zur Herstellung des Bauteils darf kein FCKW verwendet werden (siehe TL-22) Werkstoff muss frei von CADMIUM-Zusaetzen sein (siehe TL-24)

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Teil schwer brennbar nach TLX-789 Teil schwer brennbar nach ZY-789 Teil geprueft nach TLP-7886 Geruchstest nach TLX-334 1 Rand verlängert 3 Löcher hinzu Gewicht von 0,145Kg in 0,135 Kg geaendert 3 Löcher entfallen 3 Löcher entfallen

Fig. 10-5: Master data sheet as XML file

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Master data sheet – version

GOODCAR AG

XY1.522.044.00 - 003

Bei Uebermittlung schutzfaehiger Informationen behaelt sich die GOODCAR AG alle Rechte fuer den Fall der Patenterteilung vor. Jede Verfuegungsbefugnis incl. Kopier- und Weitergaberecht bei uns. In case of communicating patentable information all rights arising in the event of a patent grant remain with GOODCAR AG. All rights of disposition particularly for copying or distributing are reserved. 3D model - version Simplified drawing - version Part number – version

XY1.522.044.00 - 003

XY1.522.044.00 -003

CAD system

CAD system

CATIA version 4.2.4

CATIA version 4.2.4

XY1.522.044.00-003

Sheet no.

1 Name1

Name2

Traeger fuer Verlaengerung

Sitzkissen

AS Extension

Seat cushion

Version

Cabrio, Japan Created by

Schulz

Dept./Tel. XYZ / 5501-234

Approved by

Released by

Maier

Mueller

Tolerancing principle

General tolerances raw

DIN 7167

DIN 47-11

Material

ABS

Date

22.11.1999 General tolerances finished

ISO 2768 mk

Mat. no. 1 / proportion [%]

Mat. no. 2 / proportion [%]

Mat. no. 3 / proportion [%]

4711-01-A123 / 20

4712-02-B123 / 30

4711-03-C123 / 45

Surface protection

Surface roughness

OFL-1

ISO 1302

Edge finish

Calculated weight

DIN 6784

0.135 kg

Mat. No. 4 / proportion [%]

References

NORM 101/102 NORM PVK-12 TLX 201-A Instructions

Form as per CAD record Special features

General wall thickness: 2.5 mm No CFCs may be used in the manufacture of this part (see TL-22) Material must not contain any cadmium additives (see TL-24) Part flame-retardant to TLX-789 Part tested to TLP-7886 Odour test to TLX-334 Revision Drawing

Rev. order A6-2170/0

Position G10-11

Name Schulz

Drawing

A6-2170/0

C8

Maier

Master data

A6-2170/1

Drawing

A6-2170/2

Frank C8

Roitsch

Date 25.05.200 0 27.05.200 0 18.10.200 0 2.1.2001

Rev. text Edge extended 3 holes added Weight changed from 0.145 kg to 0.135 kg 3 holes omitted

Fig. 10-6: Example of a check output __________________________________________________________________________ Copyright VDA

VDA Recommendation 4953

11

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Comparison of VDA 4953 XML format with STEP

As exhaustive investigations have shown, the master data defined in VDA 4953 can be displayed on corresponding constructs in accordance with STEP AP214. AP214 offers an internationally standardised, semantic data model (modelled in EXPRESS) with an objectoriented structure that is used beyond industry and application boundaries (CAD, PDM. etc.). However, the generic approach necessitates a certain size and complexity in the objects to be instanced. Data which conforms to this data model can be displayed both in the “traditional” ASCII format defined in STEP Part 21 and also in various XML representations, as defined in STEP Part 28. Unlike the XML format which is specific to VDA 4953, the STEP-specific XML format is based on the EXPRESS model of the object structures to be defined (no such model is defined for the VDA 4953 data structures) and can be derived from this, i.e. it also contains its generic and complex structure. Both the multilingual option which is intensively used in VDA 4953 and the parallel description of the master data to be displayed in different company contexts can therefore be used in STEP (with the corresponding complexity of the object structures to be instanced), but are not generally supported by the current generation of processors. It is therefore recommended that the attribute-oriented structure of the VDA 4953 XML format be preferred for data exchange and archiving as this has been optimised with regard to its multilingual capability and the parallel encoding of the master data in accordance with its company context.

12 Conclusion and prospects It must be stated in conclusion that it has only been possible in this recommendation to deal with some of the ideas and suggestions relating to the simplified CAD drawing which were up for discussion when this working group was set up. The reasons for this are outlined briefly below. This system is based on the assumption of a multi-system environment as actually encountered in the participating companies. In a recommendation which is intended to apply to the entire German automotive industry, the exchangeability of product information across corporate and system boundaries must take precedence over single-system solutions. All currently available commercial CAD systems offer the capability to attach the information which is still on the simplified drawing in accordance with this recommendation to the 3D CAD model and to display it. This relates to dimensions and tolerances just as much as to properties, notes and technical directives relating to geometry or revision identifications. Seen in this light, dispensing completely with the technical drawing would certainly be conceivable. However, the neutral CAD interfaces are not currently capable of transferring the additional 3D information referred to above fully and correctly. Although, therefore, these techniques can be profitably employed in a single-system landscape, the recommendation that they be used across the industry is a non-starter. Work is continuing both nationally and internationally in various standardising bodies on uniform procedures to use these techniques. To date, however, there is unfortunately a lack of reliable results. There appears little point, however, in a parallel study of these issues. It must continue to be borne in mind that displaying the design intention also requires that prior consideration be given to views of the part or assembly and the information contained. However, the procedures introduced to create a drawing layout have reached such a level of

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development with regard to application and data exchange that no benefits can currently be seen in a purely 3D approach. One future alternative to CAD data exchange could consist of exchanging 3D design information via viewing formats across system and corporate boundaries. International activities for a system-neutral viewing format are leading in this direction. The benefits lie in the greater protection for in-house design expertise and in system independence. Work will continue on the refinement of VDA 4953 while monitoring all the national and international work in this sector.

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