Major component replacements (MCRs) form a critical part of many O&M projects. As a specialized type of maintenance work, they require additional steps to configure within Shoreline.  

MCRs are modelled as follows: 

• Add a corrective maintenance task on an asset. 
• Set the task to use an HLV or a tug, depending on whether you're modeling a fixed-bottom or a floating MCR.
  • If you use a tug, you will need to add an onshore crane to your case to conduct the maintenance work. 
  • If your are using an HLV, you need to add a dedicated CTV to transport crew to the site. Check the Dedicated tasks option when you add the CTV to your case.
    
• If you're modeling a fixed-bottom MCR, add any lead times you require.

Model a fixed-bottom MCR

To follow these instructions, you will need a case configured with a base, a WTG asset, an HLV, and a dedicated CTV.

1. Click on the Build tab. 
2. Click on the Assets tab. 
3. Click on your WTG asset. 
4. Click on the Corrective Maintenance tab. 
5. Click + Add corrective maintenance. 
6. Complete the inputs for the MCR. 
   • Severity should always be set to Critical for an MCR. 
   • For Vessel, check Heavy Lift Vessel. 
   • Complete the HLV-specific inputs. 
7. Click Save. 

Add lead times

Lead times determine the length of preparation time required before work on the MCR task can begin or before a logistic can leave base to begin work after receiving a work order.

There are 3 lead times:

• CTV lead time
  • Model spot-chartered vessels that require preparation time.
  • Available on CTVs, SOVs, helicopters, and daughter craft.
  • Set in the logistic’s Activity durations tab.
  • Only takes effect when the Spot chartered option is checked on the logistic.
• HLV lead time
  • Set at the logistic member level or when first adding the logistic to your case.
  • Applies to the HLV when conducting an MCR.
  • The process for an MCR:
    • Lead time triggered upon task creation.
    • Any additional tasks assigned to the HLV during the lead time are bundled together and carried out by the HLV in a single charter period.
    • Upon completion of the bundled maintenance tasks, the HLV demobilizes and the charter period ends.
    • A new lead time is triggered by the next maintenance task requiring an HLV.
• Task lead time
  • Applies at the task level, i.e., regardless of the logistic used.
  • Applies in addition to any logistic lead times.
  • Multiple lead times are considered consecutively.
  • The logistic lead time is only triggered once per charter, when the charter period begins.
  • The task lead time occurs on each task.

Add CTV lead time

1. Open any Shoreline Design case.
2. Click on the Build tab.
3. Click on the Logistics tab.
4. Add a new, or click on an existing, CTV.
   1. If adding a new logistic:
      1. Check the Spot chartered option.
         
      2. Click Save.
   2. If editing an existing logistic:
      1. Click on the logistic in the Members tab.
      2. Check Spot chartered.
      3. Click Save.
5. Click on the Activity Durations tab.
6. Enter a value for the Lead time.
   
7. Click Add (if creating a new logistic) or Save (if editing an existing logistic).

Add HLV lead time

1. Open any Shoreline Design case.
2. Click on the Build tab.
3. Click on the Logistics tab.
4. Add a new, or click on an existing, HLV.
   1. If adding a new HLV:
      1. Enter a value for the Logistics lead time.
         
      2. Click Next.
      3. Make changes to the inputs you require.
      4. Click Add.
   2. If editing an existing HLV:
      1. Click on the logistic in the Members tab.
      2. Enter a value for the Logistics lead time.
      3. Click Save.
      4. Click Save again.

Add task lead time

1. Open any Shore Design O&M case.
2. Click on the Build tab.
3. Click on the Assets tab.
4. Click on the relevant WTG asset or add a new one.
5. Click on the Corrective Maintenance tab.
6. Create or click on a maintenance task.
7. Enter a value for the Task lead time.
   
8. Click Save.