Datastream 7i calculates the following critical values for equipment:
Minimum and maximum critical value—Datastream 7i calculates the minimum and maximum critical value for equipment inspection aspect points based on the formula defined for the aspect and inspection point.
Retirement date—Datastream 7i calculates the retirement date of the equipment using the latest inspection results and the min/max critical value. Datastream 7i uses the latest inspection results to calculate the trend (slope) based on the linear regression method. The slope is then used to determine when the line reaches the critical min/max value. This date is the retirement date.
Remaining life—The remaining life for decreasing inspection aspects (Aspect time dependency is linearly decreasing) is the critical minimum retirement date minus the current data. For increasing inspection aspects (time dependency is linearly increasing), the remaining life is the critical maximum retirement date minus the current date.
Next inspection date—Datastream 7i calculates the next inspection date by multiplying the remaining life and the percentage of remaining life, determined by the criticality code of the equipment, the risk focus for the aspect/point combination, and the confidence rating recorded on the inspection result.
Refer to the following table for next inspection date considerations:
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Scenario |
Result |
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Datastream 7i can locate the criticality code, confidence rating, and risk focus combination in the criticality index. |
Datastream 7i locates the criticality code, confidence rating, and risk focus combination. For example, if there are 1000 days of remaining life and the criticality code % equals 25, then the next inspection date is 250 days from the current date. Note: If the length of time before the next inspection (as a percentage) is greater than the criticality index max time, then Datastream 7i uses the max time to determine the next inspection date rather than the criticality code percentage. |
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Datastream 7i cannot locate the criticality code, confidence rating, and risk focus combination in the criticality index because the risk focus is missing. |
Datastream 7i locates the criticality code and confidence rating combination when the risk focus is empty.
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Datastream 7i cannot locate the criticality code, confidence rating, and risk focus combination in the criticality index because the confidence rating is missing. |
Datastream 7i finds the lowest percentage associated with the criticality code and risk focus combination to calculate the next inspection date. |
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Datastream 7i cannot locate the criticality code and risk focus combination because the risk focus is missing. |
Datastream 7i finds the lowest percentage associated with the criticality code. |
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Datastream 7i cannot locate the criticality code. |
Datastream 7i generates the next inspection date equal to the retirement date. |
Follow these steps to calculate critical values.
Open the Calculate critical values and next inspection form (IBCALC).
Location—Click to select the location of the equipment.
Department—Click to select the department of the equipment.
Equipment class—Click to select the equipment class for which to calculate values.
Category—Click to select the equipment category for which to calculate values.
Equipment—Click to select the equipment for which to calculate values.
All equipment—Select to calculate the min/max for all equipment; otherwise, Datastream 7i only selects equipment that had inspection data changed.
Changed values only—Select to display only critical values that have changed.
Calculate—Choose one of the following options:
Calculate critical values for the equipment—Select Critical value.
Calculate the next inspection date and the estimated withdrawal date of the equipment—Select Withdrawal date.
Calculate critical values, the next inspection date, and the withdrawal date—Select Both.
Click from the reports toolbar. Datastream 7i calculates the values and prints the report.