DAC Value Stream Mapping 2 — Questions and Answers
Question 1: In Value Stream Mapping, what does 'takt time' represent?
- The time it takes to complete one unit of work
- The rate at which work must be completed to meet customer demand (Correct answer)
- The total elapsed time from request to delivery
- The time spent waiting between process steps
Correct answer: The rate at which work must be completed to meet customer demand
Takt time is the available production time divided by customer demand rate, representing the pace work must flow to satisfy customers.
Question 2: Which type of waste in Value Stream Mapping refers to producing more than what the customer currently needs?
- Waiting
- Motion
- Overproduction (Correct answer)
- Defects
Correct answer: Overproduction
Overproduction is considered the worst waste in Lean thinking because it creates additional inventory, space needs, and other downstream wastes.
Question 3: When a DAC coach facilitates a VSM workshop, what is the recommended first step after assembling the team?
- Draw the future-state map
- Identify and agree on the product family or value stream scope (Correct answer)
- Calculate cycle times for each step
- Implement kaizen improvements immediately
Correct answer: Identify and agree on the product family or value stream scope
Scoping the value stream by selecting the product family ensures the team maps the right flow before gathering any data.
Question 4: In a VSM current-state map, a 'push' arrow indicates what about the flow of work?
- Work is pulled by downstream demand
- Work is scheduled and released without regard for downstream capacity (Correct answer)
- Work is blocked and awaiting approval
- Work is automated and self-scheduling
Correct answer: Work is scheduled and released without regard for downstream capacity
A push arrow shows that upstream processes push work downstream regardless of whether the next step is ready to receive it, often creating queues.
Question 5: What is the primary purpose of calculating 'process efficiency' in a Value Stream Map?
- To determine team velocity
- To reveal the ratio of value-added time to total lead time (Correct answer)
- To measure defect rates across the stream
- To allocate budget for process improvement
Correct answer: To reveal the ratio of value-added time to total lead time
Process efficiency = value-added time ÷ total lead time, exposing how much of the elapsed time actually adds value for the customer.
Question 6: Which symbol on a Value Stream Map typically represents an external customer or supplier?
- A triangle with an 'I' inside
- A factory or building icon (Correct answer)
- A lightning bolt
- A circle with an arrow
Correct answer: A factory or building icon
External customers and suppliers are depicted as factory/building icons positioned at the top corners of the VSM to represent the boundaries of the value stream.
Question 7: In Disciplined Agile, how does Value Stream Mapping support the 'Optimize the Whole' principle?
- By focusing improvements on the single slowest team
- By providing a systemic view that reveals interdependencies and systemic waste across the entire flow (Correct answer)
- By enforcing standard WIP limits on individual teams
- By replacing retrospectives with flow analysis sessions
Correct answer: By providing a systemic view that reveals interdependencies and systemic waste across the entire flow
VSM exposes the end-to-end system, preventing local optimization that improves one step while degrading overall flow—aligning with DA's goal to optimize the whole value stream.
DAC Value Stream Mapping 2
In Value Stream Mapping, what does 'takt time' represent?