When we have a moderate to complex challenge, we need a way to find out where we are (at least roughly) and to plan a way to get to our goal (subject to ongoing adjustment).

This section includes some roadmaps for the "industry standard" six sigma process improvement cycle known as DMAIC.

We have found these roadmaps useful in navigating the many steps and options in a typical improvement project.


The "DMAIC" cycle, popularised in the six sigma literature, originated in Motorola and General Electric in the 1990s.

It is not a particularly elegant mnemonic, but it has proven to be fit for purpose, and as such we choose to use it, with comments as appropriate, rather than to propose a substitute. 

The DMAIC cycle is an adaptation of Dr Deming's PDSA (Plan, Do, Study, Act) learning cycle. It is a means of organising goals, tasks, observations and decisions such that one can develop shared knowledge at the same time as limiting risks - and getting things done.

Note that the cycle begins and ends with line management. It is a response to a business problem, usually sponsored (and resourced) by the business unit. At the end of the cycle, the solution is embedded back into the business. In between times, we follow the project cycle in sequence from Define to Control. 

Mapping Improvement Tools to DMAIC

Whilst there are many resources available that catalog tools for improvement, it is often a challenge to figure out how they fit together.

The following sections offer a suggested flow of activities through each phase of the DMAIC cycle, showing where and when each tool might usefully be employed. These flows are not rigid prescriptions, but they do offer a logical continuity that supports good practice.

Here is an overview of the end-to-end flow:

DMAIC activity flow

Click here for a pdf version.

The "Tools" section of this website offers commentary on selected tools that may be helpful to supplement the usual "how to" guides in most Lean Six Sigma publications.