Developing Quality Analysis
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Investigating quality issues involves the use of lots of numerical data, some simple charts which can be used to aid the decision making process include:


FLOW CHARTS - Mapping the process out is common amongst all quality systems after all, if you do not understand the process, you begin to improve it. Use the data found in process mapping to decide upon areas where to have Kaizen.

Find out in depth information. Look at all your processes from the customer backwards. You need to begin with understanding what the customer wants in terms of product, quality and quantity of need (apply marketing logic).

Find out as much information as possible. How does the product move around your workplace?. Look at batch sizes, machine times, scrap rates, operator training, etc. Analyze which processes are adding value to the product.

Observe product deliveries to customers and raw materials from suppliers. Find out about customer returns, and your business returns to suppliers.

This should give you an idea of what your product flows are. The operations strategy section of this web-site suggested that we must aim for as much value adding processes as possible. So identify from your process mapping which areas need improving - machine times, returns, etc.

RANK ORDER CHARTS - The logic behind rank order diagrams is very simple, it is based on Pareto’s law. Pareto suggested that 80% of the effects are generated by 20% of causes, in other words 20% effect 80% of the results.

Using the logic a little further, a rank order chart is a simple chart that shows, a item, or in this instance it could be a quality issue against the number of times the issue has arisen. For example you could use data of customer returns and why they have been sent back to your business. You may find that the reasons could be several, round them up into main categories and see which is the biggest area with problems.

This when plotted in a bar chart will show the areas where you need further investigation, in other words it will graphically bear out the biggest problem areas. Rank order diagrams are a very simple graphical tool, and are only useful to analyze simple problems with a few identifiable solutions.

CAUSE & EFFECT DIAGRAMS - Cause and effect diagrams, are very simple. The basic concept of a cause and effect diagram is to generate a fishbone diagram where all the causes of a problem against the effect (the effect is the fishes head with all the scales of the fish being the causes)

Cause and effect diagrams are best generated in brain storming sessions, when you are talking to the operators about making improvements. You can use them to view historical attempts at solving quality issues have worked out, get the operators involved, see if your proposals for improvement will work or not.

Cause and effect diagrams are useful, a lot of organisations do use the diagrams on quality control documents such as concession sheets where a cause and effect diagram must be completed every time there is any defective material. These diagrams would then be analyzed on a regular basis, to bring about improvements in product build.

FUTURE STATE - Develop a future state where you want your business to develop. By mapping the process, we should identify areas for improvement. By looking at rank order we observe further areas for improvements. Using cause and effect diagrams we see what has worked and what has not. The final state is to review and apply all we have learnt to how we get to where we want to be.

There are numerous other methods for analyzing your business for improvement, the above examples are for illustration purposes only, please be sure to read other quality publications.

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(c)  Est 08/00 - Last Updated 28/05//2001