Dear Wendy,
It was a pleasure to learn the Green belt from you and you made the whole learning process enjoyable and very easy to take in.
The black belt exam is tomorrow, and again it has been an absolute pleasure to be taught by Michele.
Once again, thankyou.
Yours
Sean
To identify sources of variability using historical or current data:
Provides objective solutions to questions which are traditionally answered subjectively
Works for differences in means, or Variances (Standard Deviations), or proportions
Y = f(x)
DOE was originally developed in 1930’s by Sir Ronald Fisher to improve agricultural methods Fisher used DOE to maximise the yield of agricultural crop (Y) by changing the key process inputs; fertilizers & seed type (x’s) he DOE approach allowed Fisher to understand the main effects of the inputs, and the interactions between the inputs which impact the process output
The objective is to logically organise changes to 2 or more input variables (x’s) and evaluate if any variable, or any combination of the variables, significantly affect the output (Y)
What is Design of Experiments?
A DOE is a set of tests on the process output with at least 2 process inputs, each set at 2 or more levels
The key principle behind the DOE technique is to create a perfectly balanced design which includes an equal combination of process settings
Consider the example below with 3 key process inputs, each set at the high end (1) and low end (0) of their respective specification (or process variation) limits
during the months of July and August there will be several green and black belt session for Lean Six Sigma; all events will be held in the Maritim Hotel in Würzburg.
Zentral und unweit des Hauptbahnhofs erwartet das stilvolle Maritim Hotel Würzburg seine Gäste. Direkt am Mainufer gelegen, bietet es einen herrlichen Ausblick auf die Festung Marienberg, die hoch über der Stadt thront. Die barocke Innenstadt mit ihren zahlreichen Sehenswürdigkeiten lässt sich bequem zu Fuß erkunden. Elegantes Ambiente, verbunden mit herzlicher Gastfreundschaft, und der direkte Anschluss an das Congress Centrum Würzburg schaffen ideale Voraussetzungen für jeden Reisezweck.
Wilbur and Orville Wright ran a bicycle repair shop in Dayton, Ohio USA but set to designing and building the first aeroplane in their spare time working in their shed!
So how did two hobbyists manage to achieve what many well funded, full time, industry backed inventors had failed to achieve?
They collected the existing knowledge on what experiments and tests had already been carried out then studied the results.
They soon realised that many thousands of hours and dollars were being spent for very little time in the air – 5000 hours of design & build time for 5 seconds air time was typical.
They identified 3 critical knowledge areas:
Between 1900 and June 1903 the brothers:
Devised
Discovered
They conducted and meticulously recorded extensive experiments.
These often challenged and proved wrong the existing ‘knowledge’ and wisdom of the time.
Detailed design Variability in the process is reduced here through high levels of standardisation of skills, processes and the designs themselves. This helps eliminate waste and rework which allows greater flexibility of capacity. Detailed standardisation also maximiseslearning and continuous improvement.
Prototype /Tools Two sets of prototype tooling are usually produced, not to test solutions but to choose the different sub-systems and check their integration. Engineering changes will not be accepted after this phase. This is an intensive period for system design manufacturing and quality engineers.
Set based engineering enables many different solutions for a design can be worked on and matured at one time. As the development time increase and moves closer to the start of production unsuitable solutions are stopped but kept on file so potentially could be used for the next new product. The main advantage of set based concurrent engineering is that if the design concept that is chosen fails to meet customer requirements it can be quickly replaced by a robust and mature alternative solution.
Conventional engineering usually starts with the generation of new concepts and ideas too, however the main difference is that the final solution is agreed at a very early stage of the development. This could be before all the other component final designs are decided/understood. Therefore, as the design stages mature if problems are found the solution may have to be reworked several times to ensure it still meets the customer requirements. The major disadvantage of this process is that usually problems are not found until later in the development stages, sometimes as late as after the start of manufacturing. Fixes problems that occur at this stage is much more expensive as you are now trying to change actual components instead of designs on paper.
A Lean product development process typically has four phases:
E.g., Toyota, Ford, Nokia and others,
We understand that we are not Toyota !!!! However, it is important to understand some of the main differences between the Toyota culture and conventional business cultures when they develop new products as it will help you see where we can make changes to grow stronger as a company. Also, it will enable you to understand where development systems have originated from.
There is a long list of techniques that characterise the flow, pull and perfection parts of the Lean idea .
Notice how must time is always given to ‘Quick Changeover’; this is important since whilst things are stopped, the value stream is not flowing
Notice also that there isn’t any “Do this!”, rather what we learn are techniques to improve the flow of value streams .
If you can’t flow then pull is the next step .
And you can not do it all at once, so every improvement is a step on the way to perfection, but you never get there .