The construction industry is one of the only industries with declining productivity. Tools like BIM, IPD, and Lean aim to reverse this trend. Set-based Concurrent Design is a Lean alternative to the traditional iterative design loops and enables projects to be designed 10 to 15 times faster.
4. What is Set-Based Design?
• Iteration in design is part value added and
part waste
– Understanding the problem and range of
solutions is value added
– Rework and time delay is waste
• “Posing alternative design solutions as sets,
rather than as point solutions is the strategy
at the heart of…set-based design.”
• (Ballard, Lean Construction Institute, “Positive vs Negative
Iteration in Design”)
6. Iterative Design Set-Based Design
• Sequential processing adds
time
• Release incomplete work for
others to start evaluating
• Simultaneous evaluation of
options
• Select best alternative as
quickly as possible to move to
next stage
• Carrying multiple options allows
more time for analysis
• Defer commitment to avoid
premature decisions with
incomplete knowledge
• One design contribution can
invalidate all previous work
• Identifying a problem with an
option reduces the design
space but does not trigger
rework
8. Set-Based Design
1. Divide design into interchangeable
chunks
2. Multiple simultaneous designs for each
chunk
3. Evaluate Combinations
4. Select a combination set
• Choosing by Advantages
5. Swap chunks at roadblocks
13. Design Sets
Combinations: n1*n2*n3…nn= many sets
Massing: 7 options
Roof Structure: 4 options
Skin Design: 6 options
7*4*6=168 design sets
Which is the best option?
14. Choosing by Advantages
• The Fundamental Rule of Sound Decision-making:
• Decisions must be based on the importance of advantages.
• Pros & Cons = double counting
1. Identify Attributes:
• Cake vs Cereal for Breakfast
• Calories
• Taste
2. Identify Difference in Attribute Value:
• Cake for breakfast = 500 calories
• Cereal for breakfast = 200 calories
• Difference = 300 calories
15. Choosing by Advantages
3. Identify Advantage
• Calories:
• Cake has 300 more calories
• Cereal has 300 fewer calories
• Advantage:
• Cereal’s advantage is 300 fewer calories
• Cake has no calorie advantage
• Taste:
• Cake tastes very good.
• Cereal tastes okay.
• Advantage:
• Cake’s advantage is it tastes much better
• Cereal has no taste advantage
16. Choosing by Advantages
4. Evaluate the Importance of the Advantage
5. Select the option with the highest Advantage
• Cereal for breakfast
Cake Cereal
Calories No Advantage 0 300 Fewer Calories 10
Taste Tastes Much Better 5 No Advantage 0
5 10
19. The Design Partnership LLP
Architects + Planners
Radically Accelerated Schedule
• Typical Project Schedule:
• 30 to 45 minutes per SF for design.
• Radically Accelerated Schedule:
• 30,000 SF in 4 months – Programming through CD
3 minutes per SF for design (10 to 15 times faster)