The System Selection and Prioritization

DOE-STD-1052-93

The following formula may be used to determine system ranking for a single

or two-unit plant:

NOTE:

LCO hours for multi-unit sites may be considered as shown

in the formula.

System score =

1.0 * [UDOL]

+ 0.04 * [LCO (Ul) + LCO (U2)]

+ 0.1 * [Survey results]

Where: U1 = Unit 1; U2 = Unit 2; * = multiply

NOTE:

The formula may be modified for a specific PM program

enhancement objective by changing or adding additional

factors along with appropriate weighting coefficients. For

example, a plant with a well-established PM program and a

strong performance record may have an objective to optimize

resources by selecting systems with a large number of PM tasks

for possible reduction while not affecting safe and reliable

operation of the system. To consider the impact of the existing

PM effort, a factor may be added to the formula that

represents the number of existing PM tasks per system or cost

to perform the tasks. Tle weighting coefficient selected should

be representative of the importance placed by management on

that factor of the formula.

7.1.3

The system selection and prioritization process should be used for the plant

systems deemed most important for nuclear safety, reliability, or economics.

Plant management should review and approve the systems selected and their

ranking. If two or more systems have equal ranking, plant management should

decide the final ranking that establishes the sequence in which the systems

should be evaluated.

It may be advisable to begin the enhancement effort by conducting a pilot

study of one system. If a pilot study is to be conducted, it may be best to start

with a system that has an unacceptable failure rate. Another criteria that may

be used for the pilot study is that a relatively simple system containing

mechanical, electrical, and electronic components be selected so all major

technical disciplines may gain experience from the study. The primary

objective of the pilot study is to refine techniques and establish guidelines for

analysis of future systems. It should be recognized that the number of systems

selected for detailed evaluation determines overall scope of the PM program

enhancement effort and the resources needed.

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