Do You Have control Charts ?

Do you have control charts within your operations ? I love control charts, but I don't see them readily used. A control chart can be used in many different ways and can be a key indicator of process stability and critical control points (CCP).

For example a CCP could be a temperature check on a blast freezer, the control chart will only have Lower specification limits and upper specification limits , no need for UCL & LCL but you can include them if you want to.

Put every temperature taken into the control chart. Now lets presume that an issue with the product has occurred, the product is not to temperature and cannot be dispatched to customer.

Because you have a history of checks on the control chart you can see if the temperature of the freezer ever dropped below the (LSL) this quickly give you confidence in the freezers stability, and now gives you a different focus.

Data loggers are available to monitor freezer temps.

Many other Control checks can be inputted into control charts, and can help in customer complaints/ investigations into quality etc.

We always have customer specifications limits when making the product, these are provided by the customer = USL & LSL product cannot be above the USL and cannot be below the LSL.

Control limits = the voice of the process, this is a calculated by mean +/- 3 standard deviations. This is all about the the empirical rule that says within 3 standard deviations we will capture 99.77% of all products made.

If products fall between the UCL & LCL this is called common cause = expected variation if products fall out of UCL &LCL this is called special cause and should be investigated.

Now let me clarify.

Just because the product is within the expected tolerances UCL & LCL this doesn't mean they should not be investigated, because the tolerances are based on 3 +/- standard deviations, it does not mean that you have the desired standard deviations.

I always look at it this way, usually USL & LSL are customer / government regulations, the UCL/LCL is opportunity to increase our quality and reduce our costs.

We want the correct mean = Close to target

With a low standard deviation aligned with our production yield

#opportunity?#data?#quality?#manufacturing?#consumergoods?#fmcgindustry?#sigma?#spc?#foodandbeverageindustry?#leadershipdevelopment?#processimprovement?#continousimprovement