Model-Centric Design

1. Model-Centric Design Danny L. Kahler, P.E. Session T31 4:00 p.m. – 5:00 p.m. August 29th, 2006 ASQ Annual Conference Energy & Environmental Division Design & Construction Division Tucson, Arizona

2. Speaker Introduction • Danny L. Kahler, P.E. • Civil Engineer • Bridgefarmer & Associates, Dallas, TX • 20+ years of engineering experience • ASQ Senior Member • ASQ CQA, CQM, CQE and CSQE

3. Vocabulary • Model - A simplified representation of a system at some particular point in time or space intended to promote understanding of the real system • System – A system exists and operates in time and space • (Definitions obtained from Society for Modeling and Simulation International)

4. Vocabulary (Continued) • Model Centric Design – All significant design processes extract information from and update changes to a digital model that represents the real system

5. Traditional Design Technology • The “model” is represented by lines and numbers on rectangular sheets • Each sheet only shows small section of the design • Visualizing the proposed design requires significant practical experience • Changes to the design are difficult • Large labor forces are required for drafting

6. Enabling Technology • Computer software that allows a design to be drawn using real world units in the same coordinate system that will be used for construction • Computer networks that allow multiple users to to see the latest version of any design component in it’s actual location

7. IT’S NOT ABOUT SOFTWARE! • Software packages are just tools that help us work with the data • We use software to retrieve the data, analyze it, manipulate it, put it back in, and present it • Model-centric design is about improving the way we use the data to make design decisions

8. Software Won’t Improve Anything • Design firms continue to invest in the latest software with little improvement in real productivity • Managers eventually turn deaf ears to production staff requests for each new “killer” application • Senior designers still rely on plan sheets to make design changes

9. We Need Model-Centric Thinking • Firms can separate pure design from construction document drafting • Managers can make choices about hardware and software investments based on actual productivity needs • Senior designers can base their decisions on the actual design, not limited sheet views of it

10. Plans Only Plans Visualization Plans Model Roundtrip Engineering Plans Model Model-Centric Plans Model Model Only “What’s a model?” The plans build the model Plans and model coexist The model builds the plans Pure design (no more plan sheets) Evolution of Model-Thinking

11. Do We Still Need Plans? • Agencies will continue to require traditional plans for many years to come • With the Model-Centric approach, the sheets just become views of the model • Each printing of the sheets reflects the most current version of the design model

12. Why Change the Current System? • Design Among Multiple Agencies • Tighter Project Schedules • Design/Build Project Teams • Increased Cost of Errors • Increased Cost of Disputes • Increased Cost of Personnel • Fewer “Seasoned” Engineers

13. What Motivates Us to Change? • Better use of technical staff • Less impact from design changes • Improved visualization of the project • Improved communication with clients and contractors • New methods of discovering and eliminating design & construction conflicts • New design practices to match improvements in construction & survey technology

14. What are the Benefits? • Allows shorter design schedules • More production with less staff • Designers doing design not drafting • Portability of design to other platforms • Clients have more influence during design • Faster response to client changes • Reduced potential for errors • Reduces drudgery of plans production • Better communication with construction

15. What do Design Firms Need? • People trained to communicate in the “language” of design models and real-time design changes • Development of guidelines to help predict revised production rates and labor costs • Establishment of new skills in how to control and assure the quality of the model • We need Model-Centric Quality Assurance

16. Model-Centric Quality Assurance Model-Centric Quality Assurance occurs when the evaluation of adequacy of a design is based on the integrated review of the actual design model rather than a fragmented inspection of individual views (plans)

17. Traditional Design QA • Document Based • Multiple Iterations of Construction Plans • Heavy Focus on Appearance • Frustrating Amount of “Drafting” Comments • Reviewer Reward based on Volume of Comments Generated

18. Implementing Model-Centric QA • Requires standards for model definition - these standards may already be hidden in agency CADD standards • Needs standardized or compatible software that faithfully represents the proposed design model to the reviewer

19. Example of Model-Centric QA Problems with storm sewer profiles found early in the design process

20. Model-Centric QA can be more than review • If the reviewer and designer are on the same software platform, an experienced reviewer can often provide feedback of what process error or errors probably caused the design flaw • QA can evolve from basic third-party product inspection to a team member that provides a value-added analysis of needed design process improvements

21. Taxonomy of Model-Centric QA • Fit • The static 3-D Integration of the Project • Flow • Things the project must transport: storm drainage, sewage, vehicles, etc. • Function • Ability of subsystems to do their jobs: signals, gates, message boards, roadway signs, etc.

22. Can we improve Model-Centric QA? • By borrowing Software Quality Concepts: • Validation • Verification • Accreditation *Terms obtained from DOD sources

23. VALIDATION • Validation: The process of determining the degree to which a model is an accurate representation of the real-world from the perspective of the intended use of the model • Does the model show us how the components of a proposed design will actually fit together?

24. VERIFICATON • Verification: The process of determining that a model implementation accurately represents the developer’s conceptual description and specifications • Does the model represent a design that will meet the performance requirements if constructed?

25. ACCREDITATION • Accreditation: This is the official certification that a model is acceptable for use within the context of a specific objective • Is the model sufficiently detailed to produce accurate construction documents ready for bid?

26. Can Contractors Take Advantage of a Design Model? • Some contractors already request source design files, and often report the files have fewer errors than the signed and sealed paper plan sheets • Agencies can establish design contract requirements for designer-validated models adequate for bidding purposes

27. Model-Centric Construction • Machine control from the model • Inspection without stakeout • Real-time status of construction progress • True “As-Built”

28. How can Model-Centric thinking reduce project costs? • Fewer review documents • Faster turnaround • More efficient use of manhours • Decreased communication errors • Decreased project risk • Early resolution of disputes

29. Future of Model-Centric Design • Contractors will begin to expect reliable models from owner agencies in order to prepare more competitive bids • Owners will respond to contractor demands by expecting designers to deliver validated design models • Stress of system change may force some people out of design and encourage others to progress faster • Clients will have the option to conduct real-time reviews of the design model instead of waiting for a submittal

30. Where to Get More Information • Danny Kahler, P.E., Texas • ASQ Design and Construction Division • Software Vendor, i.e Bentley, Autodesk, Trimble, etc • LandXML Committee • State Departments of Transportation

31. Questions?

32. Thank you for your attendance Now we can all go hit happy hour