Single point lessons, or SPLs, taken in the context of total productive maintenance (TPM), are defined as lessons or subjects that can be described in a page or less and explained in five minutes or less.
For a TPM Kaizen event, from where SPLs are mostly known, they are utilized to outline a specific operation that is performed by the machine operator to make the equipment more reliable and efficient. Whether it is how to calibrate a scale, change fonts on a printout, or the safe removal of a plastic wrapper, the SPLs are all short, concise and to the point.
But why do we limit ourselves to only Kaizen events for SPLs? Standardizing an operation in every facet of the manufacturing operation will have a positive influence on the amount of success the company achieves or expects to achieve.
SPLs, while having a lot in common with written maintenance procedures, differ in a few aspects. An SPL, as previously mentioned, is only on ONE operation that will be performed. It outlines the steps necessary to perform that one operation in a standard fashion. On the other hand, a maintenance procedure can be best described as a series of SPLs combined into one procedure, with the complete description of a procedure often being hours long. A maintenance procedure is performed in a standard fashion as outlined in the procedure's details and can be many pages long, or as few as three.
In everyday usage, the SPL plays an important role in assisting the operator to successfully execute a commonly performed task. For example, there may have been a concern raised about the many different ways a task is done by different operators. With all operators following the specific SPL for the process, there is an achieved state of standardization and optimization. The operators and machine will perform more efficiently, thus becoming more productive for the company.
So why don't all companies utilize SPLs? A lot has to do with the cultural mind-set of a past generation. In the past, operators were allowed to slowly learn an operation and make mistakes along the way. Today, in the fast-paced manufacturing world where downtime is counted in minutes and line success is dependent on the piece count each day, the equipment must run constantly at the optimum speed. Operators have to do it right the first time because if too many second or third attempts are needed to correct a problem, it could spell a sudden career change for that operator. Also, some more experienced operators believe that if they write down their secrets, they will have no job security!
With the advances in mechanization occurring at such a fast pace, it is impossible for companies to totally retool their plants every few years with the latest and greatest. Rather, they employ the equipment that has served them very well for a long time and improve on its design to maximize their output.
The Bureau of Labor statistics show the average age of a skilled operator is in the 50- to 60-year range, meaning that in 10 years or so, the now skilled operators will retire, taking all the expertise they have gathered over the years with them. There needs to be a program to instruct new, younger hires in the skill set and knowledge required to work with some degree of success on the older equipment that is still in use. Without such a program in place, a steady increase of downtime and frustration on the part of the operator or mechanic will be evident. The days of "take your time and learn it" are gone, replaced by the fast-paced production line where seconds count and operators need to know exactly what has to be done and how to be able to do it competently.
A single point lesson is invaluable for accomplishing this transfer of knowledge to the newer, less experienced operators. But take it out of the TPM context and it now can be several pages long, while still focused only on the one aspect of the operation that has proved itself over time to be a matter of conjecture on exactly how it should be performed or how the equipment should be set.
Writing an SPL with a degree of accuracy first begins with a talk with a supervisor to determine if the company already has a procedure for the applicable task that can be done efficiently and still be safe. If none is known, move on to the operators who perform that task. Ask how they do it and record their method completely. After talking with the operators and watching them all perform the task, talk with maintenance to see what the operator's manual has to offer. If you are seeing just some steps from the manual being performed by the operators, this is a good thing. It is a case of tribal knowledge being verbally passed down to new operators and something always being left out or changed in the teaching is common. Once a decision is made on standardizing a single operation, ask a maintenance and operations supervisor to verify it to be correct and complete.
Pictures are a universal language. Take pictures of critical steps in the lesson (e.g., screenshots or pictures of controls). These can be invaluable to operators who use English as a second language.
Writing the descriptions for the steps in the lesson can be challenging. They need to be written clearly, using words that are easy to understand, and be short in explanation and to the point. The last thing you want is unnecessary verbiage in a description that might confuse the reader in understanding what you are trying to get across to them.
When designing the page, do NOT make it all technical. Remember, your audience are operators, not engineers. Design the page in a manner that is easy to follow and understand. If necessary, take the lesson from applying your lockout-tagout (LOTO), by using a sequential, logical progression through the entire single point lesson. Remember, it is called a single point lesson for a reason, so only focus on that one particular task or aspect you want to achieve. You should be able to give the written SPL to anyone to follow and, if written correctly, will result in the optimum outcome.
When you are satisfied with your SPL, give it to a supervisor for a test run with a group of operators. If all is well and no further value-added information needs to be included, print copies for every operator and go over it with them to be sure they understand it. Laminate one copy to be left on the machine, either attached to it or placed in a binder that is kept by the machine for reference.
Given time, this method will begin to standardize all aspects of a machine's operation. It will decrease downtime, eliminate personal preferences and ensure optimum settings and methods are in consistent use.