Lean

Lean is a systematic approach to identifying and eliminating waste (activities that consume resources without creating value for the customer) through continuous improvement. It originated in manufacturing but has been successfully applied across all business functions.

The five Lean principles:

• Define value: Understand what the customer actually values
• Map the value stream: Identify all steps and eliminate those that do not create value
• Create flow: Ensure value-creating steps occur in tight sequence
• Establish pull: Produce only what the customer needs, when they need it
• Pursue perfection: Continuous improvement toward zero waste

Types of waste (muda):

• Transport: Unnecessary movement of materials, data, or information
• Inventory: Excess work in progress, unused features, or stockpiled materials
• Motion: Unnecessary actions by people (manual processes that could be automated)
• Waiting: Idle time waiting for approvals, information, or upstream work
• Overproduction: Building more than what is needed or before it is needed
• Over-processing: Doing more work than required to meet customer needs
• Defects: Errors that require rework, correction, or disposal

Lean in software development (from Mary and Tom Poppendieck):

• Eliminate waste
• Amplify learning
• Decide as late as possible
• Deliver as fast as possible
• Empower the team
• Build integrity in
• See the whole

Lean tools and techniques:

• Value stream mapping
• 5S (Sort, Set in order, Shine, Standardise, Sustain)
• Kanban boards and pull systems
• Gemba walks (going to where the work happens)
• A3 problem solving
• Root cause analysis (5 Whys, fishbone diagrams)