AutoCAD© Elemental (2D) Drawing Standards Model

Autodesk has a well-defined base model for establishing a drafting standard for its 2D AutoCAD© application (as well as many of its verticals). The drawing standards (DWS) file structure, in conjunction with one or more templates (DWT), enables any CAD Manager to develop, audit, and maintain accountability and compliance with a drafting standard regardless if a corporate policy exists or if a departmental best-management practices guideline is defined.

By defining the DWS parameters, you are well on your way to developing a comprehensive 2D-based drawing standard. The structure and design of a DWS file is based upon the four major components of drawing standardization commonly used within the AutoCAD environment (e.g., Layers, Linetypes, Text Style, and Dimension Styles). These components make up the foundation of all templates, blocks, and other customized entities created for use within the application. This, in and of itself, may satisfy the basic needs of CAD management but will not establish a corporate benchmark for file management, regulatory compliance, or industry protocols. For this level of detail an additional level of support and administration must be developed.

The intent of this article is to help the reader develop a general approach to CAD standardization where none may not currently exist. The following diagram depicts an elemental standardization model and forms the cornerstone for a drafting standard that can be adopted as the corporate needs expand.

dwsm001

The following sections will highlight the components that comprise each of the seven elements of a basic drafting standard and define how the pieces can fit together to form the overall structure of a fundamental standards model.

A working knowledge of the AutoCAD© components mentioned herein is presumed. For additional instruction on one or more of these components please consult the Autodesk website and/or the application’s Help feature.

Note: For the purpose of this document the use of the terms CAD standard, Drafting Standard, and Drawing Standard are interchangeable with each being used to help clarify the subject of discussion.

1.0 Autodesk Defined File Structure

dwsm1At the core of every AutoCAD drawing are four primary components that must have, as a minimum, one of each identified. The degree of complexity is of course, user definable, however a conservative approach should always be considered when developing these components. This will be self-evident when attempting to audit a drawing file created using these foundational elements. Furthermore, these elements should be automated whenever possible through Templates; Block usage; Menu selections; custom programming, etc. to avoid misinterpretation of standard protocols.

1.1 Layers

The minimum amount of layers defined is dependent upon the AutoCAD (and/or vertical) application being used as some layers are mandated and cannot be removed. User defined layers may result from corporate needs for data segregation, or for entity creation, display, publication, and editing purposes.

Each layer represents a diverse property value and may lend itself to be widely abused and misinterpreted unless a data dictionary and illustrative documentation exist for reference purposes. Any layering scheme (regardless of its complexity) should be well defined to avoid misuse whenever possible.

1.2 Linetypes

Linetypes are defined within the ACAD.LIN (or other company specific *.LIN) file and must be loaded into each drawing prior to its use. Default linetypes that are consistent across all disciplines of drawings should be preloaded in the templates or other user defined entities when created.

All linetypes (including those defined by the base CAD application) should be represented in a data dictionary and properly illustrated to avoid misuse. This becomes paramount when extended ASCII codes or non-standard text fonts are used to display symbols within the linetype.

1.3 Text Styles

Text styles may be easier to standardize and maintain as each defined style is dependent upon an installed text font. However, care must be taken when establishing standard text styles as specific fonts can become non-supportive or obsolete over time. Eliminating or purging a predefined text style/font can become a challenging task especially if it is embedded within blocks or templates used throughout the organizational structure.

1.4 Dimension Styles

Dimension styles are as diverse as Layers and usually vary across drawing disciplines and the intended use of all or part of a drawing. Each dimension style is controlled by numerous system variables and settings within the Dimension Style Manager, thus each dimension style used should be well defined and illustrated to ensure proper use. This is fundamental to any corporate standard given that at any time during drawing creation or editing a dimension style may be overridden.

2.0 User Defined Parameters

dwsm2Beginning with board drafting, the drafter was forced to scale or fit specific details within a given physical space, oftentimes this was a pre-printed sheet unique to each company. While the use of Model Space affords the CAD user the ability to work in an unlimited amount of space, at some point the work may need to be printed. Thus, the parameters established in the Page Setup Manager allows for multiple sheet sizes to be used within Paper Space layouts. This method of Paper Space Management is critical to established drafting standards and protocols.

In association with each paper space layout are specific printer/plotter requirements that are managed within a Plotter Parameter (.PMP) file utilizing the Calibrate Plotter wizard and a plotter configuration (e.g., .PC2 and .PC3) file. Depending upon the plotter settings and corporate standards there may also exist a Plot Style Table (.STB) file and/or a Color-Dependent Plot Style Table (.CTB) file. Such files should be well documented with copies of each file archived for redistribution or to restore an altered or missing file. This is especially true if drawing edits and printing is performed outside of the controlled environment of the corporate structure.

If a Drawing Management System is utilized for publishing non-native drawing formats (i.e., .PDF, .DWF, etc.) for consumption by others outside of the CAD environment the plot parameters must be established and documented in case they are modified for use by an alternate output device.

3.0 User Developed Entities

dwsm3After the foundational drawing elements and user defined parameters (Sections 1 & 2) have been established they should support the development of a Master Template file (e.g., Drawing.DWG) that all other templates (.DWT) and blocks (.DWG) may be based upon.

All AutoCAD verticals and many 3rd party applications provide a robust menu, ribbon panel, and/or toolbar set. However, none of these will be inclusive to every industry and corporation, thus the need to create additional interfaces may exist. The Custom User Interface (CUI) may expand beyond the need of simple commandline syntax and block insertions to include custom programming code (i.e., VB, LISP, VLISP, etc.); and/or external files defined within the Program Parameters File (PGP).

4.0 Corporate/Industry Parameters

dswm4Regardless of the industry, there are most likely Federal, State and/or Local government regulations that impact specific document retention and recordkeeping protocols, some of which may be directly or indirectly related to the drawing files created or edited within an organization. As such, a company’s legal counsel should be engaged to ensure compliance with all respective Regulatory Standards.

Oftentimes an industry group will exist to develop comprehensive processes to promote a consistent and standardized approach to general work practices. If pertinent, these Industry Standards should be adopted and applied to the company’s CAD standards.

The CAD standard should be specific about the procedures, protocols, and drafting practices that must be adhered to on a continual basis. However, there may exist a suitable alternative to achieving an end result. Such alternatives should be defined in a Best Management Practice (BMP) document to provide a general guideline for preferential methods for drawing creation and editing. The end result should be to provide guidance when undefined conditions arise or when an alternate end-user preference is acceptable.

Independent of all of these are Corporate Policies, Procedures, and other Relative Standards that may affect the design and construction of drawing content. A review of these documents with their respective owners should occur to ensure compliance with all aspects of CAD drafting and design.

5.0 Institutionalized CAD Standard

(User Defined Parameters)dswm5a
(User Developed Entities)
+             (Corporate/Industry Standards)
Institutional CAD Standard

The results of the previous sections make up various aspects of a drafting standard, however at this point they are still fragmented. For a small centralized organization this may suffice as communication and work processes may not be hampered by the restrictions of larger corporate settings or de-centralized locations.

Regardless of the corporate structure, the tools, processes and procedures developed thus far must be vetted by all end-users to ensure that these foundational elements are working in concert with each other as well as the expectations of all concerned parties. This should result in the culmination of a comprehensive drafting standard. This should also be compiled into one document that can be easily navigated and used for training and reference. Upon completing these steps and incorporating them into a document/drawing management system (if used) a 2D CAD Standard has emerged. This standard must have the approval and support of the company’s leadership team and such acceptance should be well communicated to all end-users of the document to avoid misuse and the misappropriation of drawing files and their supporting documentation.

6.0 Corporate Document Management Protocols

dswm6Whether an enterprise document/drawing management system is deployed companywide, or a basic file structure is defined using minimal resources locally, file maintenance procedures must still be documented and communicated as the official protocol for all CAD related files. A fundamental file management system should transcend mere file maintenance (i.e., drawing dissemination, printing, etc.) and provide guidance for file naming and specific tasks and workflows required to create, edit, and house drawings along each phase of development.

In conjunction with file maintenance and management a formal auditing process should be developed and documented to ensure that drafting standards are adhered too and accountability is placed at the correct level of drawing development and editing.

When utilizing a template (DWT) file, a corresponding Drawing Standards (DWS) file should be created by which all related drawings will be audited against for compliance assurance. AutoCAD supports the use of multiple DWS files allowing for discipline or task specific drawing audits. When altering any portion of the DWS structure, care must be taken to ensure that all corresponding templates are updated accordingly to avoid loss of data or problems arising during a “CheckStandards” command or other related auditing processes.

7.0 Corresponding Standards Development

dswm7While 2D CAD remains a core function of engineering design and construction it may not be the primary application deployed. For many organizations 3D modeling, BIM, GIS or other data-driven applications are used to meet a specific need that is beyond that which 2D CAD can provide. As such, other areas of concern may need to be evaluated that affect the functionality and intent of the 2D CAD standard.

7.1 Integration Standard

Other systems may exist that are dependent upon the information housed in a CAD drawing and/or the drawing management system (e.g., G.I.S., CMMS, etc.) and all applications should be researched to determine how data interoperability can be achieved without duplicating a dataset or restricting the use of the native system.

7.2 Autodesk Vertical Application Standards

If additional vertical applications are utilized, then modifications to the drafting standard can be expected. These changes may be amended to the existing standard or a separate document may be created specific to the vertical application used.

7.3 3D Design Modeling Standard

3D applications will add another level of complexity to a CAD Standard beyond that of any 2D drawings. In some cases, the processes used in a 3D application can nullify or render some portions of the 2D standard obsolete. If this is the case, then care must be taken to properly document these variances from both the 2D and 3D perspectives.

7.4 Sustainability Program

Developing a CAD standard does not end once the document has been printed and placed on a shelf. The document must be reviewed on an annual basis or whenever the software is amended or company policies and procedures alter any function of the content. Moreover, anyone affecting the integrity of a drawing should be trained on the use and intent of this subject matter and understand the ramifications of failing to comply with the established standard.

8.0 Conclusion

In this model the basic constructs of the AutoCAD product, along with regulatory and corporate procedures, define the corporate drafting protocols that should be adhered to when creating or editing a company sponsored drawing.

All drawings and supporting file structures should be maintained within a formal document management system. This system should complement the drafting standard for file naming and data distribution to all concerned parties.

Additional standards and data integration schemes may be deployed to compliment and support the drafting protocols in use. The length at which an organization may go to deploy 3D modeling, BIM, GIS, or any Autodesk vertical application varies greatly and must be evaluated as the corporate business model and internal needs dictate.

A CAD standard can be as simple as a base template and drawing standards file (DWT and DWS respectively), or a comprehensive manual spanning multiple disciplines and applications. Whatever the level of competency, a standard must exist to maintain consistency, accountability, and compliance – not to mention the sanity of the one charged with managing the finished product.

The following bank model is supplied as a template to begin the process of mapping a CAD standards model for a given organization.

DWS Model