Lean Software Development — major processes & flow maps
Lean measures lead time across the entire stream and waiting time between steps.
Guide · Updated · Source
1. Value-stream overview (idea to production)
Idea to production stream
How work moves from demand to delivery with measurable lead time across the full value stream.
- Value-stream overview (idea to production)Frames the end-to-end path from idea through production delivery.
- StartDemand or a validated idea enters the value stream.
- Core steps (see walkthrough below)Work progresses through shape, plan, build, verify, release, and learn phases.
- OutcomeDelivered value reaches production with traceable elapsed time.
Value-stream overview (idea to production)
Start
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v
Core steps (see walkthrough below)
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v
Outcome
Note: lead timeLean measures lead time across the entire stream and waiting time between steps.
2. Waste identification loop
Waste identification loop
A repeating cycle that maps current flow, finds waste, and standardizes proven countermeasures.
- Current stateThe team documents how work actually moves today.
- Checkpoint / gateA review point asks whether waste is identified and actionable.
- refine or escalateCountermeasures need rework or a higher-level decision before proceeding.
- Continue flowValid countermeasures advance into the live process.
Waste identification loop
Current state
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v
Checkpoint / gate
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+-- no ──► refine or escalate
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yes
v
Continue flow3. A3 problem-solving flow
A3 problem-solving flow
A structured, concise path for analyzing complex problems and validating countermeasures.
- A3 problem-solving flowFrames the A3 format as the bounded container for the investigation.
- StartA complex problem worth structured analysis enters the flow.
- Core steps (see walkthrough below)Each A3 section builds on the prior with forced conciseness.
- OutcomeA reviewed countermeasure plan ready for execution or standardization.
A3 problem-solving flow
Start
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v
Core steps (see walkthrough below)
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v
Outcome4. Pull-based work selection
Pull-based work selection
Work enters execution only when capacity exists, limiting WIP and queue waste.
- Pull-based work selectionFrames selection by available capacity rather than pushed demand volume.
- StartReady work waits in a governed queue until a slot opens.
- Core steps (see walkthrough below)The team pulls the highest-priority item matching current capacity.
- OutcomeBounded work in progress flows to completion at sustainable pace.
Pull-based work selection
Start
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v
Core steps (see walkthrough below)
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v
Outcome5. Phases A–F (Lean focus areas)
| Blueprint phase | Lean focus | Key metric |
|---|---|---|
| A Shape | Define value; avoid over-specification | Time from idea to "ready" |
| B Plan | Last responsible moment; pull-based commitment | Queue time before start |
| C Build | Small batches; eliminate task switching | Cycle time per item |
| D Verify | Built-in quality; catch defects at source | Defect escape rate |
| E Release | Automate deployment; reduce batch size | Deploy lead time |
| F Learn | Production feedback; close the loop | Time from deploy to insight |
6. Seven wastes in software (reference)
| Manufacturing waste | Software equivalent |
|---|---|
| Overproduction | Features nobody uses |
| Inventory | Partially done work (branches, specs not implemented) |
| Motion | Task switching between unrelated work |
| Waiting | Blocked items; waiting for review, approval, environment |
| Transportation | Unnecessary handoffs between teams or phases |
| Over-processing | Gold-plating; excessive ceremony for the risk level |
| Defects | Bugs, rework, misunderstood requirements |
7. Flow details (walkthrough)
Value-stream overview — Every piece of work flows from demand to delivery. Lean measures the total elapsed time, not just active work time. The gap between active and elapsed is waste (waiting, handoffs, queues).
Waste identification — Map the current state, identify waste using the seven-waste taxonomy, analyze root causes, design and test countermeasures, then standardize what works. This is a continuous cycle, not a one-time exercise.
A3 problem-solving — A structured approach to complex problems. The A3 paper format forces conciseness. Each section builds on the previous; the review validates reasoning quality.
Pull-based selection — Work is pulled when capacity exists, not pushed based on demand volume. WIP limits prevent overloading. This is the operational mechanism behind "deliver as fast as possible."
8. Authoritative sources & further reading
- Wikipedia — Lean software development — Overview of principles and history.
- Wikipedia — Toyota Production System — Manufacturing roots.
- Wikipedia — Value-stream mapping — The diagnostic tool for waste identification.
- Lean Enterprise Institute — Practitioner community.
- Agile Alliance — Lean software development — Glossary entry.
Full curated list: External reference URLs (methodology guides).