Lean software development

Lean software development (LSD) is a translation of lean manufacturing and lean IT principles and practices to the software development domain. Adapted from the Toyota Production System, a pro-lean subculture is emerging from within the Agile community.

The term lean software development originated in a book by the same name, written by Mary Poppendieck and Tom Poppendieck. The book restates traditional lean principles, as well as a set of 22 tools and compares the tools to corresponding agile practices. The Poppendiecks' involvement in the Agile software development community, including talks at several Agile conferences has resulted in such concepts being more widely accepted within the Agile community.

Lean development can be summarized by seven principles, very close in concept to lean manufacturing principles:

Lean philosophy regards everything not adding value to the customer as waste (muda). Such waste may include:

Industry research revealed these software development wastes:

In order to eliminate waste, one should be able to recognize it. If some activity could be bypassed or the result could be achieved without it, it is waste. Partially done coding eventually abandoned during the development process is waste. Extra processes like paperwork and features not often used by customers are waste. Switching people between tasks is waste. Waiting for other activities, teams, processes is waste. Motion required to complete work is waste. Defects and lower quality are waste. Managerial overhead not producing real value is waste.

A value stream mapping technique is used to identify waste. The second step is to point out sources of waste and to eliminate them. Waste-removal should take place iteratively until even seemingly essential processes and procedures are liquidated.

Software development is a continuous learning process based on iterations when writing code. Software design is a problem solving process involving the developers writing the code and what they have learned. Software value is measured in fitness for use and not in conformance to requirements.

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