Six Sigma/DFSS Flashcards
Briefly explain the concept of Six Sigma quality on terms of both the metric and the implications for the customers of companies who achieve it.
The Six Sigma metric is defects per million opportunities (dpmo) and performance at a Six Sigma level equates to 3.4 dpmo.
Customers of organisations operating at this level can have high confidence in the products delivered, even when they are complex assembled products as the rolled through yield will still be high. Also, as variation is reduced the negative consequences of variation within tolerance i.e. variable product performance, early wear out) should also be reduced.
Briefly contrast the focus of improvement for Six Sigma and Design for Six Sigma.
Six Sigma focuses on improving existing processes (i.e. improving conformance to design intent). It is more limited than DFSS as some parameters will be too expensive to change once the process is running (e.g. tooling changes on large presses). DFSS starts at the concept phase and so has more leverage in terms of designing processes which meet design intent but also, crucially, can focus more on ensuring that design of both product and processes is done to deliver maximum customer satisfaction at lower cost.
Describe the 5 steps of the DMADV process associated with DFSS, indicating key activities at each stage
Define - Project plan, business case, charter, risk management
Measure - Customer needs data, prioritise, VOC translated to CTQ characteristics, establish target specifications
Analyse - Identify key functions, design for manufacture, design for reliability, generate design concepts
Design - Product and process planning, high level and detailed design, process capability studies, predicted performance, design experiments.
Verify - Ensure the design meets customer requirements, pilot production and test functions.
Discuss whether the Six Sigma approach and associated tools, structures, and behaviours is likely to effectively address issues of organisational change. Draw conclusions regarding the likely efficacy of Six Sigma in generating sustainable change.
Failure to Deliver Tangible Results
The Six Sigma approach is to use focused projects (approximately 3 months in duration) to deliver tangible business benefit by assessing potential impact in the early phases. The black belts provide a focused resource to deliver benefit to the organisation. The risk is that black belts may exaggerate improvements due to performance pressure and reward mechanisms.
Breakthrough Blindness
Six Sigma initiatives link the projects strongly to organisational goals through the governance procedures so that relevance to core goals is assured. Processes are they key focus of Six Sigma projects so that the solutions are clearly relevant.
Drowning in Detail
The DMAIC process allows for a good guide through the process of improvement and avoids over-documentation through standardised reporting formats.
Everything is a High Priority
The strategic drive and links of Six Sigma help to ensure that clear priorities are established on agreed criteria. Each project is assessed against these criteria early in it’s life cycle and continuously throughout the project.
Old Performance Measures Block Change
The DPMO performance measure provides a common metric whereby all processes can be measured in a consistent fashion, reducing the potential for confusion driven by old metrics.
The Voice the Employee is Not Heard
The use of expert-led change is problematic in this regard as there is a potential for change to be ‘done to’ the vast majority of employees who may feel uninvolved. Also reward mechanisms for black belts may encourage them to push action through.
For the most part, Six Sigma effectively addresses may of the issues associated with change, but it is weak on ensuring the voice of the people is heard. This may be a very significant issue as involvement is crucial to the success of change. There are also potential issues with the exaggeration of potential and actual benefits which may lead to under-delivery and disillusionment.
