This is a short paper that Hal Macomber and I put together to contrast Lean and Six Sigma in Project-Based Organizations.
Lean and Six Sigma are generally understood as improvement approaches. Both can be comprehensive approaches for managing the organization. Lean is about focusing on what is valuable to the customer – all else is considered waste. Six Sigma is about improving quality through reducing process variation. Both approaches use some variation of Walter A. Shewhart’s Plan-Do-Check-Act (PDCA) approach for putting the scientific method into everyday use. A blend of Lean and Six Sigma is becoming the norm for modern process-based companies.
Organizations that have ongoing operations (healthcare, manufacturing, services) have a pre–existing way they do their work. Planning how to do the work every time the work is done is not essential because of the repeated flow, assembly line, or standard operating procedures that are re-used. For process-based work, the work advances either on the arrival of material (push system) or the replenishment of material (pull system). The organization in process-based situations is rather stable. People tend to work with the same people most of the time.
Organizations that do one-off production or do projects (design, construction, large procurements, information technology implementations) start their work by designing the production system. They do this in planning conversations. The best practice for doing that planning directly involves the people who will be performing the work of the project. Work advances in projects through commitment-making by the performers of the tasks. The project organization is created new for each project. People often don’t know each other or have limited contact with each other up to the start of the project. Once the performers have accomplished their tasks they often leave the group. Eventually, the whole team typically disbands and moves onto other projects.
Unlike process-based work, planning must continue on projects in anticipation and in response to the changing conditions as the project unfolds. Planning is an essential aspect of successful projects. Lean Project Delivery starts with an emphasis on improving planning. This is akin to the Six Sigma focus on stabilizing process capability (Cpk) using statistical process control. Once we are able to complete what we set out to do when we set out to do it, then we are in a position to bring the general improvement practices to both projects and processes. Lean Project Delivery incorporates methods uniquely suited to the project setting.
• conditions of satisfaction (customer value)
• network of commitments (value streams)
• paced production (continuous flow)
• right-to-left scheduling (pull principle)
• on-going retrospectives and continuous improvements (pursuit of perfection).
There are no Six Sigma methods or tools that are available to address those concerns.
The risk of overlooking this constant re-establishing of the production system is attempting to fit a project into a predefined set of production system tools. We might say “do it like the last project” or attempt to map the flow of a project, only to find infinite variations and differing needs during the next project. The result contains unconsidered waste.