Obvious Areas For Improvement

External Defects

  • Anything you have recently been audited or formally rejected for
  • Anything you haven’t been audited or rejected for, but you know is out of specification or not meeting regulations
  • Anything you inspect and/or contain to protect the customer
  • Anything you cover for by having a guy in the customer’s plant, etc.

Internal Defects

  • Any scrap issues, parts, or materials
  • Anything you rework/recycle in house – you should keep accurate track of rework by defect
  • Anything you have a poka yoke for – you should know how often the poka-yoke is catching something and then try to figure out how to prevent it rather than catch it

Efficiency/Capacity Issues

  • Anywhere you make less parts than expected
  • Anytime you are currently working non-customer driven overtime
  • Any process where you are running slower than expected cycle
  • Any process or machine with downtime
  • Any process with premium freight costs
  • Any process that has added labor to make the required cycle

Other Plant Cost Drivers or Measurables

  • Any cost driver with a negative variance may point to a project
  • Any plant metric that is important and runs at an unacceptable level or with large amounts of variation is a good indicator for a project

Less Obvious Areas for Improvement

Material Utilization

  • Any part which uses more than the standard amount of material
  • Any part in which the amount of material used varies – reduce the variation and shift usage to the lowest limit

Understanding Process Variation

  • How much variation is there in your incoming materials and/or process parameters and how does this affect your output?
  • Where do you need the input controlled to always have a good output?
  • Can you scientifically adjust your process to compensate for changing material, weather, etc.?
  • Can your Black Belt help your supplier do a project to control the incoming product where you need it?
  • Does understanding your inputs allow you to produce a good part using less material?


  • For high failure rate or high replacement cost items, what causes the failure?
  • Can you reduce the failure rate by understanding and controlling the process?
  • Study how to predict failures so replacements can be made during scheduled, rather than unscheduled, downtime.

Efficiency/Capacity Issues

  • Learn how to speed up or slow down your cycle time by changing your process inputs.
  • Use this knowledge to produce customer overtime parts on straight time, or to do scheduled preventive maintenance during the week on straight time.

General Guidelines for Project Selection

  • Any project should have identifiable process inputs and outputs.
  • A good Six Sigma project should never have a pre-determined solution.
  • If you already know the answer, then just go fix it!
  • For projects that have operator or operator training as an input, focus on ways to reduce operator variation, therefore making your process more robust to different or untrained operators.
  • All projects need to be approached from the perspective of understanding the variation in process inputs, controlling them, and eliminating the defects.

Example #1

Problem: We are experiencing slow cycle time at Station 30 because we are getting bad parts from Station 20 and have to rework them.

Non-Six Sigma Solution: Rebalance the line in order to do the rework and keep your cycle time below specifications while not spending extra labor cost.

Six Sigma Solution: Investigate and control key inputs that contribute to making a bad part production at Station 20.

Example #2

Problem: We have had two quality related issues reported this year for missing armrest screws.

Non-Six Sigma Solution: Add sensors to detect screws further down the line. If screws are missing, operator manually fixes.

Six Sigma Solution: Determine process inputs causing missing screws. For example, auto gun does not always feed correctly due to air pressure variation. Either study range required for 100 percent operation and control in that range, or find way to make gun more robust to range of variation experienced.

Looking for Six Sigma Project Examples?

You can find detailed Lean Six Sigma and Kaizen projects and case studies at Six Sigma Project. Enter coupon code “iSixSigma” (without quotes) and receive $5 off any Lean Six Sigma project case study of your choice.

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