Skip to content
LeanSuite - Lean Manufacturing Software

Book summary · Quality and Six Sigma · Intermediate

Lean Six Sigma: summary and review

Combining Six Sigma Quality with Lean Speed

By Michael L. George. First published 2002.

The short answer

Michael L. George, who led the George Group consultancy, argues that Six Sigma and lean fix different halves of one problem. Six Sigma cuts variation and defects but, in his words from an interview, has no tool to control lead time. Lean controls work in process and flow, so it shortens lead time and removes the cost of queues. His answer is to run both inside one project structure aimed at the processes customers and shareholders care about most. It is a deployment book: read it to decide how to organize improvement, not to learn the tools.

Read it if

  • Your pain is long lead time and piles of work in process as much as scrap, and you need a rule that links the two for your finance team.
  • You are designing or auditing a multi-site improvement program and want to see what deployment planning and belt roles involve.
  • You already have trained belts and want the case for adding pull and WIP limits to their projects.

Skip it if

  • You want to learn statistics or a lean tool step by step. The tools get one chapter out of fifteen.
  • You run one plant and want a supervisor-led, Toyota-style approach. The deployment model here is corporate and belt-centered.

When it pays off: When a defect-reduction effort and a lean effort are running separately at your site, or when you are about to launch one and decide how to staff it. Read it before you certify anyone.

The core ideas, in plain language

  1. 1

    Quality and speed need different tools

    George says Six Sigma tools do not control lead time (pull systems are an example) and lean tools do. A defect-rate project will leave a three-week order cycle where it was.

  2. 2

    Lead time follows work in process

    The book builds on Little's law: lead time equals the items in process divided by the completion rate. Cut the queue in half and the wait halves with no one working faster. The book names this the law of velocity.

  3. 3

    Most delay sits in a few steps

    As practitioners summarize it, about 20 percent of activities cause 80 percent of delay. Map the stream, measure cycle efficiency (value-added time over total lead time) and attack those steps first. Treat 80/20 as a heuristic to test.

  4. 4

    Complexity costs more than defects

    A secondary summary reports that George puts product and service variety ahead of poor quality or slow flow as a source of cost and WIP. The shop-floor implication: look at variety and options before the next kaizen event.

  5. 5

    Speed also speeds up analysis

    George's example: a designed experiment of about 100 runs finishes five times sooner if lead time drops 80 percent. Fast cycles make the statistical work practical.

How to use it on Monday morning

  1. 1

    Compute lead time from queues

    Pick one value stream. With the supervisor, walk it with a clipboard and count the pieces or orders waiting at each step, then record the daily completions for a week. Divide total WIP by daily completions and compare with what order tracking says.

  2. 2

    Write the cycle efficiency down

    Split that lead time into time someone adds value and time work waits, and record the ratio on a current-state map as your baseline.

  3. 3

    Pareto the delay, not just the defects

    List steps by waiting time and circle the top few. Then run a week of defect tallies on the same stream. Where the same steps top both lists, you have your first project.

  4. 4

    Cap one queue for a week

    Mark floor spaces or use cards to cap WIP in front of the worst step. Have the supervisor log each time the cap is hit, and track daily completions.

What to be careful about

  • Corporate scale, consultancy origin

    George led a consulting firm, and the contents run from CEO kickoff to belt selection. Jamie Flinchbaugh warns that building an elite problem-solver group apart from the floor contradicts lean's frontline engagement.

  • Whether the blend is a method

    Mark Graban cites Geoffrey Mika's cat-and-poodle image: the two come from different roots and can run side by side, not as one blended method. Tony Bendell (2006) found the literature on combining them limited, though he judged they can be merged.

  • Repetitive, and it dates from 2002

    One Goodreads reviewer says the useful content could fit in 30 pages. It predates Toyota Kata and the coaching practices that now accompany lean, and its 80/20 and complexity claims are heuristics, not research results.

Lean Six Sigma compared with The Six Sigma Way

Choose George when lead time, WIP and changeovers hurt as much as defects. Choose The Six Sigma Way, which covers Six Sigma only, when the open question is governance: roles, project selection and customer-defined quality. Neither teaches statistics, so add Understanding Variation.

Read the summary of The Six Sigma Way.

Tools and templates on LeanSuite that go with it

Book details

Bibliographic details of Lean Six Sigma
TitleLean Six Sigma: Combining Six Sigma Quality with Lean Speed
AuthorMichael L. George
First published2002. McGraw-Hill, 2002. Some catalogs list the subtitle as Combining Six Sigma Quality with Lean Production Speed; the first-edition ISBN records use Lean Speed. George followed it with Lean Six Sigma for Service (2003) and a pocket toolbook (2004).
Edition shownHardcover, first edition, McGraw-Hill, 2002
ISBN-13978-0071385213

Details checked against public records on 7 October 2026. Other editions have other ISBNs. We carry no affiliate links.

Key terms

Lean glossary

FAQ

Questions about Lean Six Sigma

More lean books

Back to the lean books hub for reading paths and filters.

Rather see it on your own problem?

Bring the problem you are stuck on, and we will show you on a call how LeanSuite handles it.

Schedule Demo

Pass it on

We want LeanSuite to be the best place on the internet for lean help. If this was useful, send it to someone on your team or in your network who needs it.