PM Work Sheets

Excerpt from John W. Rushton’s book, Effective Maintenance Management Using Planned and Preventive Maintenance.

Since work sheets are a vital part of ALPM, they must be functional.  All items on the PM sheets must be completed every time.  Work sheets should have space for the planner or foreman to enter minor repairs, and space for the craftsman to list needed repairs for backlog. 

If the PM line people consistently fail to complete every item on the sheets, it is likely that the sheets need modification.  The sheets must be dynamic, and changes should be made as necessary to encourage strict compliance.

Rushton International usually labels each sheet with a letter (A, B, C, etc.).  This is strictly for convenience, and titles like 250 hours, 7 day or 5000 miles will work.  Using alpha names, the series can go as high as H on a PM line that is tracking service activities at 125 operating hours over a six-month period.  We do all services recommended by the manufacturer when they come due, or earlier.  Normally, a good PM line will service the unit twice as often, but the equipment will spend less than half the time in the shop for service.  This is doable and will work every time.

PM SERVICE SHEET PREPARATION


PM service sheets are comprised of ITEMS (jobs) and SYSTEMS (closely related groups of jobs).
     

 Item Criteria

  1. Must eliminate a significant source of downtime or expense.
  2. Can be reasonably completed during the normal PM time frame.
  3. Can be checked for compliance.

System Criteria

  1. Must eliminate a significant source of downtime or expense.
  2. Responsibility for the entire system can easily be assigned to a craftsman or group of craftsmen.

When grouping items from a system on a PM service sheet, each item should be listed in a logical order of completion.  When designing system PM activities, you need to take into account the other PM or operating activities that may be taking place at the same time.

Before starting the preparation of the PM service sheets, you need to become as familiar as possible with the equipment and its systems.  Each system should be estimated as to the percentage of emergency or expensive repairs that the system is responsible for.  If the percentage is low, give that system a low priority.  In the real world, you have a level of manpower—don’t create a level of listing systems and items that exceeds this level.  This can destroy your whole PM program.  An example is that most new plants have the construction company furnish the initial PM service sheets.  They either hire a group or an individual that sells PM service sheets by the pound.  This group spends anywhere from six months to two years writing PM service sheets for every piece of equipment and every system in the plant.  We have seen rooms totally full of boxes of PM service sheets.  They are totally useless.   It takes more time to sort through these sheets and decide what makes sense and what does not than it takes to start from scratch and write a totally new set of PM service sheets.

 

EXAMPLE

The easiest way to illustrate the preparation of a PM service sheet is to systematically go through a system and prepare a real PM service sheet.  The fuel system for a heavy duty diesel truck is a good example:

Fuel System Emergency Downtime Distribution

Out of Fuel

40%

Fuel Pump

20%

Clogged Filter or Strainers

15%

Leaking Fuel Lines

10%

Accelerator Linkage

10%

Miscellaneous

5%

Since the fuel tank is on one end of the system and is a large source of downtime, the first item might be as follows:

  1. Fill the fuel tank with_________ gallons.  Inspect and clean the connections of the supply and return lines.

Note that this item asks the mechanic to write down the amount of fuel and to clean the connections to the fuel lines.  If the gallons are not filled out, the foreman is alerted that the unit may be going out without a full tank.  If he looks at the truck and the connections are not clean, he can be reasonably sure that this item was missed.  No tracking system in the world can replace good PM service sheets and an alert foreman.

The next logical item is the drain off the bottom of the fuel line, which is the first line of defense against clogged filters or strainers.  When you think about it, you should allow as much time to settle as possible before draining the sediment.  This indicates that it may be a good idea to drain the sediment before adding fuel. The sheet should read as follows:

  1. Drain the sediment basin into a clear glass and inspect for water or sediment. Continue until a clean sample is obtained.
  2. Fill the fuel tank with_________ gallons.  Inspect and clean the connections of the supply and return lines.

The next area is the strainer or filter area.

  1. Remove and clean sediment bowl on the strainer and filter. Clean or replace filter elements. (Fram 122)

Notice that the part is listed to assist the mechanic in getting the right element.

The next item is the fuel pump, and there is nothing you can do that makes any sense so you ignore it. The only remaining source of down time is the linkage, so the last item is as follows:

  1. Clean accelerator linkage with a solvent rag and lubricate with light machine oil.  Check for freedom of movement and spring action.

Again, this item is easy to check by noting the presence of the light machine oil. While this example is not necessarily complete or accurate for your trucks, all items meet the criteria for a good item, and the items are listed in the logical order of completion.


After the service sheets are prepared they should be reviewed with the foreman and the craftsman.  Make sure the language is clear and understood by all concerned.


Failures and emergency repairs should be continually monitored, and the PM service sheets should also be modified continually.

 

THE PM WORK SHEET WRITER

The job of writing PM work sheets can be greatly reduced with a PM Work Sheet Writer on a computer.  Time required will be reduced at least 80%.  Rushton International has developed a writer in our Sabre32 Maintenance Software that uses systems and items as a base, and makes writing a PM work sheet a mostly drag-and-drop exercise. The resulting PM work sheet is attractive, easy to use and easy to reproduce (See Fig. 4-14).  The sheet can easily be edited and fine-tuned which should be a continual process.


Most of the maintenance software packages that force the user to imbed the PM work sheets in a work order make the process of writing good PM work sheets so difficult that it rarely gets done.  If you are forced to use this type software, it is better to manually write your sheets with a word processor.  File the PM work sheets, and use a copying machine when the PM procedure is triggered.    



Figure 4-14         Sample Computer Generated PM Work Sheet

 

       

Contact us for free PM Sheets and we will be happy to help you out.

©Rushton International: Provider of maintenance consulting and maintenance management software.

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