I am going to focus on the concept of car consumption and how it relates to the importance and sage of control charts in quality management for my company.
Control charts are used to monitor variations in given a variable for the purpose of making sure that the process is on control. The types of variations are assignable or common.
Our operations department utilizes control charts as an indicator if something is going wrong. One of the variables they focus on is fuel consumption. What was really interesting to me is how specific the process of putting control charts was. The process involved factors like the type of the car, the weather conditions it operates in and the car depreciation value which relates to its usable lifetime. Each one of those affected the level of consumption and it happens that we get a reading for one of the cars beyond the control limits that will indicate that there something wrong with the car and it has to be inspected. Other control charts are prepared in the same manner for the other variables affecting the condition of the car.
As per our operations director, gathering the right set of data is the most difficult part. You will be able to obtain most of the consumption and car wear and tear variables as per industry standards or from the manufacturers themselves. One of the common mistakes is that you will base all of your charts based on them. You will have to collect your own and have a variance analysis just to make sure that you do not get misleading results at the end of the day.
What I would to add here is regardless of how prepared we seem to be by keeping an opened eye on consumption we had the occasional unexpected breakdowns of some of our vehicles. Despite the fact that the last check was completely perfect. We had other cases in which we were using the wrong limits for our charts and ended up being reactive at the expense of quality.
Would the concepts of quality management and your business relevant statistical process control charts make sure that you have the perfect quality product in the market? In my line of business, it would minimize the risks and based on experience it is not a guarantee. What about yours?