Problem Solving

There are many techniques used in trying to solve problems.  Lean Manufacturing favours using the 5 why’s approach.  This is simply asking why something has happened, obtaining an answer and asking why again in response to the answer.  This is repeated a total of 5 times so that hopefully by the conclusion of the questioning the root cause is found.  It is simple and effective, but is it always enough.  The answer to that is NO because sometimes when a question is asked, either to oneself or somebody else, the answer is not known.  Another obstacle in successful problem solving, particularly in a group situation, is having preconceived ideas of the solution without knowing the exact nature of the problem.

What are not so obvious are the hidden problems that were not covered –

• Why are the subsequent processes designed to allow bad parts to be used?
• Why were people down the line unaware of the problems up-stream?
• Mr Stat carefully looked at the good and bad parts and found a pattern of the defect, but did not ask about timing.  Patterns could be buried in the detail of when parts are run, like “this fault only occurs on second shift; or on a Friday; or when the tool has just returned from maintenance shop” etc.

• If you are forced to make assumptions during your team discussions, write them down, visually display and check them out as soon as possible.
• If people chuck in solutions or guesses, write them down, visually display, say you will come back to that later and continue along the logical path.  If you fail to acknowledge any team members suggestion, that person will turn-off and may not provide the vital clue you are seeking at a later date.

• Once the problem has been resolved has thought been given on how to prevent it happening again?
• What about the tooling used on the long studs – is that damaged?  Do you have similar tooling on other products that are in need of modification / repair?
• Do you have preventative maintenance on the tools or do you wait for them to go wrong?

What happens when as a group you cannot find the solution?  When this occurs, people on the shop floor can often make or break the successful resolution.  Keeping and retaining pertinent data logs of the processes when requested is vital and alerting the group if something amiss is noticed can give a lead.  This is particularly necessary if trials at different machine settings etc are being carried out to try eliminating or reducing the variables thought to be negatively affecting the process.  Most important of all, if the problem persists for a long time, then disappears, shout and continue to log.  When a problem disappears most people rejoice and relax.  At that point it is vital to gather all the process detail so that if it returns you can systematically recreate the OK condition and in doing so hopefully reveal the root cause.

In some situations it is possible to have a number of causes associated with a given problem.  For example lets take a financial example. 

Cash flow problem caused by e.g.

Purchasing large batches of material.

• Unable to buy in smaller lot sizes relating to our production schedule.   

• Quantity price discounts obtained.

Long production process lead-time.

• Slow changeovers.  

• Batch production instead of flow processes.

Accounts Receivables section unable to collect monies owed by customer

• Incorrect price on invoice.

• Incorrect quantity on invoice.

• Incorrect address on invoice.

• Terms not clearly stated on invoice.

• Customers deliberately delaying payment.

Each of the above items may be influencing cash flow problems but some will undoubtedly have more influence than others.  In this case the causes are known but those, which are having the greatest impact, are usually attacked first.  What should not be overlooked however is if a small cause can be effectively eliminated without expenditure of a lot of time and effort and it would not detract from solving the major causes, allow people to just do it.

Finally, I remember a very good piece of practical advice given to me from a very senior manager when fighting a particularly difficult problem.  The manager walked up, asked how it was going and after receiving a detailed account what had been tried and what we had failed to resolve, said “sometimes when it’s really difficult, as the situation worsens the answer becomes obvious, so long as you keep looking.”  Never be afraid to ask for help and don’t talk about the problem, examine it.   

If the company decides to go toward Lean Manufacturing, problem solving becomes one of the major elements of everyone’s job.  This is because without built-in safety the system will fail dramatically unless problems can be resolved very quickly.