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CUMTIMELINE

Description: In the Fleet data type, the analysis stacks the failure times of each system in the data set into a cumulative timeline, and then converts it to grouped data based on the intervals you specify. Depending on the model you are working with, this function allows you to manually build a table that shows the number of failures in each interval (Crow-AMSAA model) or the number of distinct modes in each interval (Crow Extended model).

Syntax: CUMTIMELINE (Data_Src, Row, Column)

Data_Src is the source data sheet from which the information is taken.

Depending on the model you are working with, the Row and Column parameters will return the following information:
- For the Crow-AMSAA model:
- - Row corresponds to the order of the intervals (i.e., row 1 = 1st interval, row 2 = 2nd interval, etc.).
  - Column is an index value (from 1 to 3) that returns the following information:
  - - 1 = returns the number that is specified in Row.
    - 2 = returns the number of failures that occurred in the interval. The failure numbers are non-cumulative (where each row shows the number of failures that occurred in that interval only).
    - 3 = returns the time at which the interval ended. The times are cumulative (where each row shows the total amount of operating time accumulated by the end of each interval).

- For the Crow Extended model:
- - Row corresponds to the order in which the unique modes appeared in a specified interval (i.e., row 1 = 1st unique mode that occurred, row 2 = 2nd unique mode that occurred, etc.).
  - Column is an index value (from 1 to 5) that returns the following information:
  - - 1 = returns the number that is specified in Row.
    - 2 = returns the number of distinct modes in the interval.
    - 3 = returns the time at which the interval ended.
    - 4 = returns the mode classification
    - 5 = returns the failure mode.

Remarks:

The Data_Src can be one of the following values:

If using a default data source, it must be either 1, 2, 3 or 4, as selected from the Data Source Index drop-down list.
It can take a data sheet name (e.g., "Folio1!Data 1").
It can take a variable name defined in the Defined Names window (e.g., datasource).

The Row and Column values must be greater than 0.

Examples:

The following table is for a particular data set analyzed with the Crow-AMSAA (NHPP) model. In the first configuration (row 1), there were 8 failures in the first 10,000 hours of operation. In the second configuration (row 2) there were 8 more failures in the next 10,000 hours of operation ( for a total of 20,000 hours). The rest of the data can be read in a similar manner.

The next example is for a data set analyzed with the Crow Extended model. It shows the number of distinct modes in each of the intervals. In the first configuration (rows 1 to 5) , there were 5 distinct modes in the first 10,000 hours of operation: row 1 shows that there were two BD1 modes, row 2 shows that there were three BD2 modes, row 3 shows that there was one A mode and row 5 shows that there was 1 BD4 mode.

Note that the values depend on the source data set.