Can two plus two equal eight?

Editor's note: this is the first of a continuing bi-monthly series of columns on reliability and maintenance.

Most maintenance departments profess to understanding the need for planning and scheduling and condition-based maintenance (CBM). The benefit of using them together seems shrouded in mystery. "Opening the hood" and looking at how they work together to produce results far exceeding that of the sum of the benefits of each used alone is an interesting analysis. A good place to start is a brief examination of each concept.

Planning and scheduling simply prioritize and organize work. Managers and hourly employees alike in stores, accounting, purchasing, engineering, and production must buy into the concept. Major outcomes of planning and scheduling include:

* Analysis and execution of work identified

* Detailed plans, rules, and records for the work

* Effective use of planners, supervisors, and craftspeople. These outcomes should yield cost savings, increased production, and reduced injuries.

Obviously, the primary concerns of planning an scheduling are efficiency and organization! Using planning and scheduling alone, craftspeople often continue to undergo frustration with emergencies from "surprise" breakdowns. This forces them to bypass the planning an scheduling procedures they labored so hard to deploy.

CBM has different definitions. Figure, 1 shows common definition. Note that it goes far beyond vibration analysis. The outcome of CBM is simple. It should find future failures before they manifest themselves as breakdown of equipment or a component. A breakdown is the loss of the function a component should accomplish. An example is a pump that stops pumping.

[FIGURE OMITTED]

The outcome is pure information--knowing that a item will break in the future. This in itself does not prevent any failures but does allow the following:

* Gather information about the equipment and parts influenced by the future breakdown

* Plan and schedule the repair

* Eliminate the cost of damage from a breakdown.

Repairing something before a breakdown typically results in savings of 50%-90% as a comparison of Figures 2 and 3 implies.

[FIGURES 2&3 OMITTED]

The degree of savings depends on how early one catches the fault, whether the fault is repairable on-line, and the cost of repairs. Compare finding an impending breakdown on a standard motor in stock attached to a production line scheduled for maintenance next Wednesday at 8 AM to 4 PM to the scenario where a non-stock motor failed at night and forced a shutdown of the line for repair. The second scenario will cost much more than the first as people scramble to find what is wrong and call in several trades and perhaps stores. Add overtime, production losses, and contacting suppliers to find replacements to complete a familiar picture.

CBM alone frequently results in flagging many items for repair. Only some actually undergo repair since maintenance does not use efficient work practices. This can demoralize operators and craftspeople since items they find still break instead of being repaired when discovered.

Combining CBM with planning and scheduling produces synergies such as:

* Reduced cost of spares and material

* Increased labor productivity

* Better job satisfaction

* Increased production yield

* Effective work practices

* Improved production quality.

Now it should be obvious that two plus two can equal eight by using planning and scheduling and CBM together.

To Idhammar (left) is a partner and vice president with IDCON Inc., with responsibilities and implementation support to preventive maintenance and condition monitoring, planning and scheduling of maintenance work, and root cause problem elimination. Michael Lippig (right) is business development manager and consultant for IDCON, Inc. He has more than 20 years of diverse experience in manufacturing and processing on three continents as an operator, mechanic, engineer and manager. Email the authors at: T_Idhammar at IDCON.COM Or M_Lippig at IDCON.COM