Lean Six Sigma FAQ's
Frequently asked questions and answers.
Define
Can some benefits be both hard and soft?
Benefits are either classified as 'hard' or 'soft'.
Hard benefits are those that result in an improvement to the balance sheet or income statement - they have a financial impact.
Strictly speaking all other benefits are soft.
However, it is at the discretion of a business to determine whether certain benefits, such as saving time and therefore staff cost , is calculated in £s as a hard benefit.
What is the best scoping tool to use?
Scope focusses a project on the specific process or processes that will be addressed. It identifies the boundaries of the process as well as identifying what is beyond the scope of the project.
Scope should be agreed by all key stakeholders prior to the project moving in to Measure. The best scoping tool is simply the one that helps this be achieved in the most efficient manner.
How can you tell the difference between a hard and soft benefit?
Hard benefits are those that result in an improvement to the balance sheet or income statement - they have a financial impact.
Strictly speaking all other benefits are soft.
However, it is at the discretion of a business to determine whether certain benefits, such as saving time and therefore staff cost , is calculated in £s as a hard benefit.
Who decides whether a benefit is hard or soft?
Essentially, the decision to classify a benefit as 'hard' is determined by an appointed representative of the financial division of a business. If they verify the improvements to the balance sheet or income statement then benefits can be classified as 'hard.' If they can not identify this, then the benefit should be classified as 'soft'.
If there is potential of a soft benefit becoming a hard benefit then this can be stated in the final benefits calculation for a project.
How do you know which high level CTQ characteristic is the correct one?
Kano analysis should be applied to CTQs to identify the primary (and possibly secondary) CTQ for a project.
CTQs classified as Dissatisfiers should always be addressed first.
What is the best method to collect VOC and VOB?
Initially, identify and collect existing information. Always ensure historical data is validated.
When existing sources have been exhausted, any gaps should be filled in by collecting new VOC and VOB. The best method for doing this depends on the project but could include 1:1 interviews, focus groups, questionnaires, surveys or observation.
Measure
How long should data be collected for?
In simple terms, data should be collected for the time it takes to collect a reliable and representative sample.
This wholly depends on the process and the frequency of items moving through the value stream. The data collection period for a process with high volumes will, in general, be shorter than for a process with low volumes.
It is important to take time to create a detailed Data Collection Plan to assist with identifying the data collection period.
How many people should you observe when completing a Waste Walk or Value Stream Map?
The number of people to be observed should be representative of the total number who are part of the process. For example, if a process touches 3 different teams then people from all 3 teams need to be observed.
Analyse
Should analysis be delegated to a team member or should the Project Manager do this?
Root Cause Analysis should be conducted by the entire project team.
Specific statistical and graphical data analysis should be completed by the project team member who has the best skills and expertise to complete the task. Depending on the project, this could be the Project Manager. In all cases, this should be shared and validated with the project team.
What graphs can be created using attribute/discrete data?
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Pareto Charts
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Stratified Pareto Charts
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Pie Charts
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Bar Charts
What graphs can be created using variable/continuous data?
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Histograms
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Matrix Plots
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Box Plots
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Scatter Plots
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Time Series Plots
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Capability Analysis
Improve
How long should a pilot last for?
A pilot should last for as long as is required to prove changes have been succesful.
This will be dependant on the time required to collect reliable and representative data so can often be a similar time to that taken in the data collection period in measure.
What should you do if your pilot has not made any improvements?
If the changes implemented in the pilot have not resulted in the required level of improvement then a mini-DMAIC project should be completed to understand the root cause of this. These root causes can then be addressed.
Control
When should project benefits be realised by?
A final benefits calculation should be completed at the end of the project and the expected benefits realisation timescales documented in this. This needs to be signed off by the Project Sponsor.
Who should a Handover Plan be passed to?
This person should always be the process owner.
