Understanding the Impact of Preventive Maintenance

Project Contact: Karl Kempf, Intel Corp
Proposal Contact: Phil Beyers, Ford Motor Company

Go to LFM Research Group 5 Mission Statement page

---

Background: Key to any manufacturing operation is the "care and feeding" of its production equipment. In theory, an effective preventive maintenance (PM) program will preclude any major problems with the equipment and will allow producers to maximize output, minimize cost, and assure on-going quality of the parts being produced. In reality, PM schedules are a combination of the machine/tool supplier's recommendations and any modifications required to reflect the "real-world" requirements of cost, quantity and quality. Considerations include:

• if you PM too frequently, quantity goes down and cost goes up unnecessarily (machines are precluded from production while production parts and operators sit idle, maintenance workers could be doing something more productive, spare parts are used up prematurely).

• if you PM too infrequently, quality and quantity go down and cost goes up unnecessarily (machines run past optimal PM may begin to produce marginal or scrap parts or cause emergency maintenance situations which typically take longer to fix than planned maintenance).

The challenge/problem is to plan the PM frequency for minimal impact on quantity and quality and cost.

Proposal Description: The focus of this project will be to understand the effect(s) of preventive maintenance on the quantity, quality, and cost of the parts being produced.

The deliverable will be a model that can be used to optimize the relationship between the PM methodologies being used within the various manufacturing facilities and the quantity, quality and cost levels of the parts being produced. The following is an example approach:

Develop a series of curves in an attempt to establish a relationship between the level of preventive maintenance performed and various other parameters, such as quantity, quality, and cost. Ultimately, a series of graphs with machine type on one axis (simple to complex) and relative quantity, quality or cost data on the other axis would be generated. Various curves could also be plotted on each of these graphs representing the different levels of preventive maintenance performed.

Quantity, Quality and Cost could be measured by the following parameters.

• Quantity: throughput during an interval of time ...
• Quality: % quality parts, changes in Cpk values of individual machines or processes
• Cost:Variable and fixed cost related to the parts being produced ...

The final product could be a multi-dimensional plot depicting the optimum PM approach for each machine type or class of machines.

The research topic requires ...

• a survey of participating member companies to determine the current preventive maintenance methodologies being used. (Identify the variables being considered in the determination of the various PM schedules.)

• a determination and understanding of the relationships between the variables.

• the development of an optimization model that would provide or lead its user(s) to a "best choice" preventive maintenance schedule in support of producing the maximum quantity of high quality parts at an appropriate level of cost.

Schedule: Research should last from 12 to 18 months and would include manufacturing site visitation as well as interviews with appropriate manufacturing/scheduling personnel at each site.