Decay Curves screen - HxGN EAM - Version 11.07.01 - Feature Briefs - Hexagon

HxGN EAM Equipment Rankings
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English
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HxGN EAM
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Feature Briefs
HxGN EAM Version
11.7.1

On the Decay Curves screen, you preset the equipment condition at a moment in time or at a certain usage like 250,000 miles for example. A decay curve is required when the selected Condition Protocol on the Equipment Ranking screen is set to one of the ‘decay curve’ protocols. The screen has these important attributes:

  1. Decay Curve - The unique identifier for the decay curve.

  2. Organization - Organization of the decay curve. Can be common.

  3. Description - Short description of the decay curve.

  4. Status - System Codes status entity "DCST". Select one of these options:

    1. Unfinished - This is the status where decay curve data can be changed.

    2. Approved - Data on this screen and on the Curve Point tab will be protected.

  5. Type Max - This is an integer that denotes the maximum value that can be entered in Point Value on the Curve Points tab. For example, if you are defining a decay curve for a maximum equipment age of 40, then enter 40 in this field. Or if the maximum usage of the equipment is 250,000 miles, then enter 250,000 in this field. Note that if Type is "Percentage", the system will fill in 100 for you.

  6. Type - Type of curve. Select one of these:

    1. Period Based - If the condition of the equipment is related to age.

    2. Usage Based - If the condition of the equipment is related to usage.

    3. Percentage - If the condition is related to a percentage of the age or usage.

  7. Period Based - This field depends on the selected Type. If available, the only option is "Years" at this moment.

  8. Usage Based - This field depends on the selected Type. If available, you can select one of the UOMs.

  9. Condition Score Start - Condition score at the beginning of the equipment life.

  10. Condition Score End - Condition score at the end of the equipment life.

  11. Condition Score Threshold - Condition score after which the equipment is rendered end of useful life. For further details on these condition score fields see the Equipment Rankings screen.

  12. Operational Modifier - This is an optional field for information purposes only. System Codes entity is "OMOD"

  13. Linear Asset Flag - This is an optional field for information purposes only.

    Use Markov Chains if you want the system to determine the decay curve for you. Markov Chains use a transition matrix to determine the likelihood that the equipment will be in a certain state or health after it has reached a certain state or health in a previous iteration of the chain. The changes to the state of the equipment are called transitions and the probabilities that the equipment moves from one state to another are called transition probabilities. The initial state of the equipment is assumed to be ‘perfect health’.

    Markov Chains were named after the Russian mathematician Andrey Markov.

  14. Markov Chains - Select if you want to use Markov Chains.

  15. Number of States - Specify the number of states that will be used in the transition matrix. The minimum is 2 and the maximum is 10.

  16. Curve Point Interval - The interval depends largely on your selection of Type and Type Max. If you are working with a period-based curve for 20 years and you want a condition score for every year you enter 1. The system will then calculate Curve Points for you and divide 20 by 1. But if your curve is for 100 years and you only want a condition score every 3 years enter 3 here and the system will set Curve Points at 100 divided by 3 is 33. Note that the system will cut of the fraction in this case.
    For a usage-based decay curve where the maximum usage is 500,000 miles you may want a condition score for every 10,000 miles. In that case set Curve Point Interval at 10,000 and then the system will set Curve Points at 50.

  17. Precision - Set the precision of the calculated condition score.

  18. Process Running - This check box is selected if the Regression Based Non-Linear Optimization process to calculate the Markov Transition Matrix is currently running. The Process Last Updated field indicates when that job was started.

  19. Average Percentage Error - Indicates how well the history fits the new decay curve calculated by the Regression Based Non-Linear Optimization process. Lower numbers are better.