Risk Number

In Asset Strategy Optimization, the risk number is calculated on the basis of the commonly known premise that "Risk = Probability * Effect". In Asset Strategy Optimization, you also have the option of using the maintenance duration when determining the risk number.

The data required to calculate the risk number are located in several places in Asset Strategy Optimization. Below is a list of data that you must enter in order to generate a risk analysis. The starting-point is the following formula.

Risk = Probability * Effect (* Maintenance Duration)

Chance

In Asset Strategy Optimization, the chance of a failure occurring is determined using the following factors:

• MTTF

• The MTTF weighting factor

During the set-up of an FMECA system, you specify the MTTF in a part's Failure Cause field. This number indicates a certain period of time expressed in hours, weeks, months or years. This duration is incorporated in a class, which you configure in the MTTF's factor classification. This class is associated with a weighting factor. In turn, this weighting factor is the number used in calculating the risk number.

Effect

To take the calculation further the Effect factor also needs to be determined. To do so, the number used is that of the Business Objectives. You must first decide which business objective a failure affects, as well as what the associated class is. The entity linking a failure to a business objective is the Failure Mode. The Failure Mode is configured at part level in the FMECA Grid or the FM Library, after which it becomes available as an option for Failure Cause. In this way, the Failure Cause (the failure) is associated with the effect on the business objective. Your Failure Mode selection determines which classes, and thus which weighting factor of the business objective, must be used for calculating the risk number. This, then, determines the weighting factor that will be used to calculate the risk number.

Maintenance Duration/Response Time

As mentioned earlier, the Maintenance Duration can also be incorporated into the Risk Number calculation. You can also configure weighting factors for the Maintenance Duration. You do this with the Factor Classification, selecting "Maintenance Duration".

In order to determine this weighting factor, you consider two Asset Strategy Optimization factors. These are:

• Maintenance Time in the General tab of an FBM maintenance action

• Response Time in the Corrective tab of an FBM maintenance action

These two fields contain a time value expressed in hours, weeks, months or years. By adding these two values, you get a value that is within a Maintenance Duration class. Next, this class is associated with a weighting factor. In turn, this weighting factor is the number used in calculating the risk number.