PL Scenario Assessment - Repair Chart

Take Note

This overview will guide you on how to use and interpret the Repairs section in the Scenario Assessment Module of IMS PLSS. This section is identical in both Internal and External Corrosion Tabs.

The Repair Chart section of the Scenario Assessment module, allows you to enter a specific Number of Repairs to evaluate their effect on the Remnant Life.

The Repairs section presents two straightforward repair methodologies to repair the worst Defects:

• Meter based: Defects are repaired using 1-meter repairs (e.g. sleeves with a length of 1 meter).

• Defect based: Defects are repaired individually, with one Repair per Defect.

The Meter based option provides insights into the actual Repairs required. For instance, addressing 23 individual Defects may be consolidated into just three 1-meter Repairs. Changing the methodology affects the Graph, Labels, and number of Repairs.

To change the Repair methodology:

• Select the preferred methodology by clicking the corresponding radio button above the Graph.

Simulating Repairs

The Repair Graph shows the potential increase in Remaining Life and the Traffic Light color (x-Axis, starting from the original Remaining Life) as Defects (y-Axis, starting from zero) are repaired. Defects are repaired in order of the shortest Remaining Life.

To simulate Repairs:

• Enter a numeric value in the Number of Repairs field.

• Click Save and Run in the Scenario Toolbar.

Example:

In the example above, repairing 10 Defects extends the Remaining Life to Jul 24, 2025, which is shown in the Scenario Sensitivity section.

Although the Number of Repairs is always a whole number, the dots on the graph are connected by a dotted line for clarity, as discontinuous lines would not enhance understanding. Plotting the points for repairs of individual Defects is straightforward.

For 1-meter Repairs, the algorithm works as follows: a 1-meter Repair is centered on the worst Defect (shortest Remaining Life), and all Defects covered by that Repair are marked as repaired. This process is repeated cumulatively for subsequent Repairs.

The maximum Number of Repairs is the number where all Defects are repaired. If there are no Defects, no Repairs can be specified.