House of Lean

Lean is the systematic removal of waste within a process, known as muda in Japanese. Much of our understanding of lean as a process improvement tool is a reflection of the Toyota Production System (TPS). In the parlance of TPS, the container for lean ideas and concepts is the House of Quality. Larman and Leffingwell and others have modified the metaphor to the House of Quality that Toyota leveraged to the House of Lean (HoL) to focus on the flow of work. The focus on flow makes lean concepts an important component for scaling Agile in frameworks like SAFe. Even without the rebranding, the core of lean provides a focus how work is done, which improves the flow or smoothness of work. The focus on flow reduces variance (know as muri in Japanese). Lean identifies variance from by comparing the outcome of work to development standards to expose existing problems so waste can be reduced. I am assuming that once waste is exposed that you do something about it. The concept of the House of Lean or the House of Quality has many variants. All that I have studied are valuable, however we will use the Larman/Leffingwell version of the HoL as this version seems to have found fertile ground in the software development field. The House of Lean we will explore consists of six components. They are:

  1. A ceiling or roof, which represents the goal. The goal is typically defined as delivering the maximum value in the shortest sustainable lead-time while providing the highest value and quality to customers, people and society.
  2. Pillar one (typically shown on the left side of the hours or lean) represents respect for people. Work of any sort is built around people. People need to be empowered to assess and evolve how they work within the standards of the organization. Agile reflects this respect for people in the principles of self-organization.
  3. Pillar two (typically shown on the right side of the hours or lean) represents continuous improvement. Continuous improvement, often termed Kiazen or good change, is the relentless removal of inefficiencies. Inefficiencies (waste) detract or keep an organization from attaining the goal.
  4. Between the two pillars are housed:
    1. Delivery practices that reflect the techniques used to deploy lean, such as great engineers, cadence, cross-functional teams, team rooms and process visualization. In the SAFe version of the HoL, the 14 Lean Principles often subsume a discussion of delivery practices. The inclusion in the HoL of specific types of lean and Agile delivery practices helps practitionersto clearly see the linkage between theory in the 14 Lean Principles and the two pillars of lean and the practice of developing software.
    2. 14 Lean Principles (See my interview with Don Reinertsen on SPaMCAST and my review of his book, The Principles of Product Development Flow: Second Generation Lean Product Development). The 14 Lean Principles espoused by Reinertsen are a mechanism to remove waste from the flow of work. In the original TPS, versions of the HoQ this was reflect by an element called Reduction of Mudas (reduction of wastes). Reinertsen provides a set of principles that are more easily translated to software development and maintenance.
  5. A base which represents lean/Agile leadership. Many of the representations of the HoL/HoQ call the base management support. Leadership is far stronger than support. Leadership reflects a management that is trained in lean and Agile AND believes in lean and Agile. Belief is reflected in decisions that are philosophically in sync with the 12 Agile Principles and the 14 Principles of Product Development.

The House of Lean is a convenient container to hold the concepts and ideas that began as the Toyota Production System and have evolved as tools to be less manufacturing-oriented. The evolution of the HoL to include concepts and techniques familiar to Agile practitioners have not only helped to reduce muda and muri, but also is a useful tool to help reduce overhead when scaling Agile using frameworks like SAFe.