Lean practices for software development focus on maximizing customer value while minimizing waste. This includes reducing partially completed work, extra processes, extra features, task switching, waiting, motion, and defects. Developers should take an economic view by quantifying the cost of delay. They should also manage queues to reduce wait times, exploit variability while maintaining economic impact, reduce batch sizes to improve cycle times, apply work-in-progress constraints, and accelerate feedback through small batches.

1. Lean Practices for
Software Development
@ Sandeep Yadav

2. What is Lean?
• Practices to maximize customer value while
minimizing waste.
• Deliver Quality products with sustainably
shortest lead time.

3. Source of Software Development
Principles

4. Reduce Waste
Waste Description Example
Partially done work Work started but not complete. Code waiting for testing.Specs waiting for
development
Extra processes Extra work that does not add value Unnecessary approvals.Unused
documentation.
Extra features Features that are not required or are thought of
as “Nice to haves”
Gold plating.Technology Features.
Task Switching Multitasking between several different projects
when there are context switching penalties
People on multiple projects
Waiting Delays waiting for reviews and approvals Waiting for approvals.Waiting for reviews
Motion The effort required to communicate or move
information or deliverables from one group to
another; if teams are not co-located this effort
may need to be greater
Distributed teams. Handover
Defects Defective software that need correction Incorrect Requirements. Software bugs

5. Take an Economic View
• If you want to quantify one thing ,Quantify the
Cost of Delay.
• Cost Of Delay=Business Value + Time Criticality +
Risk Reduction/Opportunity enablement.

6. Manage Queues
• Queues create longer cycle time, increase risk ,
increase variability, lower quality, decreases
motivation.
• Little's Law:
Avg wait time = avg queue length / avg processing rate
• Faster processing time decreases wait
• Control wait times by controlling queue lengths
• Make invisible visible

7. Exploit Variability
• Reducing variability impacts innovation and
hence the profitability.
• Use Spikes, Cadence, Synchronization ,
Forecasting.
• Don’t remove variability manage the economic
impact-maintain portfolio.

8. Reduce Batch Size
• Larger batch size creates longer cycle time,
increase risk , increase variability, lowers quality.
• Slice stories -points.

9. Apply WIP Constraints
• Context Switching cost.
• WIP limits help to control cycle time, identify
blockers, make wait times predictable and
prevents uncontrolled expansion of work.

10. Accelerate Feedback
• Facilitated by Small batches.
• Truncates unsuccessful paths quickly.
• Reduces risk.
• Improves efficiency of learning.

11. SUMMARY
• Reduce Waste.
• Take an Economic View.
• Actively Manage Queues.
• Exploit Variability.
• Reduce Batch Size.
• Apply WIP Constraints.
• Accelerate Feedback.