Configure the duration and logic of logistic installation and transit processes to accurately model installation time frames. You can set up processes on logistics at the input-library or the case level.
Processes are available on the following logistics:
- Heavy lift vessel
- Cable installation vessel
- Towing vessel
- Crane
- Anchor handling vessel
- Feeder
- Component transfer vessel
Below, you can find details on the process's inputs and functionality.
How processes work
Processes are not required for a simulation. You can skip processes by setting each process Duration value to 0
and deselecting any options.
Each logistic has a preset selection of processes, which are broken down into customizable steps. You can add and remove steps and complete the inputs as required.
You can also create process variations, which act as a modified copy of an existing process that you can link to an asset task.
During the simulation, processes are carried out in the order shown in the app.
When a logistic carries out a task, all the processes are scheduled together, in one continuous block, without additional time between steps.
Mobilization starts on the hour, and subsequent processes begin immediately after the previous step has been completed.
Step inputs
Steps are where you can customize the logistic processes. The above screenshot shows some inputs on a step. The actual inputs you see will vary depending on the step you are editing. Below, you can find details on each input.
Define max allowed time to wait
This checkbox enables the Max time to wait before start input box in the Parameters section of the step.
How it works
It is often crucial to plan steps sequentially with little or no time between them. For example, you can only start step 1 if you know you can also complete steps 2 and 3 without interruption.
This option provides a way to define how long a logistic can wait to start the current step following completion of the previous step, i.e., the maximum weather downtime between steps.
Leaving this setting unchecked allows the logistic to remain idle indefinitely before starting the step, providing maximum flexibility.
Crane example
A simplified crane operation for a nacelle installation might consist of 3 steps—hooking up, hoisting, and connecting—that must be carried out in a single operation. This might require the following restrictions and max wait times:
- Hooking up
- Duration: 2 hours
- Weather restrictions: None
- Hoisting
- Duration: 5 hours
- Weather restrictions: Wind speed, 10 m/s
- Max time to wait before start: 0
- Connecting
- Duration: 5 hours
- Weather restrictions: Wind speed, 5 m/s
- Max time to wait before start: 0
The three steps require three continuous weather windows totaling 12 hours where the weather limitation of each step is not exceeded. The hooking up step will not start until the simulation encounters such a weather window.
Examples
Scenario 1, no flexibility:
- Step 1:
- Duration: 10 hours
- Step 2:
- Duration: 10 hours
- Max time to wait before start: 0 hours
To complete these 2 steps requires a continuous weather window of 20 hours, as the vessel cannot remain idle between the steps waiting for good weather.
Configuration 2, some flexibility:
- Step 1:
- Duration: 10 hours
- Step 2:
- Duration: 10 hours
- Max time to wait before start: 4 hours
Here, there is more flexibility for completing the steps. The weather criteria can be exceeded, i.e., there can be bad weather, for up to 4 hours following the competition of step 1 before a 10-hour weather window opens to complete step 2. You can create more flexibility, if required, by checking the Flexible option.
Repeat
If a step requires carrying out multiple times, e.g., loading out blades, you can check the Repeat box to model this repetition without having to create a step for each loadout procedure.
Inherit task duration
O&M HLV only.
Available on the following processes:
- Mobilising
- Loadout
- Jack up
- Crane operation
- Jack down
- Demobilisation
When you check this box, the process step inherits its Duration value from the Replacement time value on the relevant corrective maintenance task.
Generally, this checkbox is used on 5.0 - Crane operation, as this is the replacement work itself.
Use this setting to define the work duration generally on the asset.
Flexible
Check this box to allow work on a step to pause and resume as weather conditions allow. On site, such pauses and restarts might occur during cable laying, due to increased wave height, or at the request of a marine warranty surveyor.
Two new inputs appear when you check the Flexible option:
- Min. work duration: The minimum required weather window for a work period to begin.
- Max wait between work periods: Acceptable weather downtime between work periods. If bad weather lasts longer than this, the step is reset, i.e., the step again requires the whole step Duration to complete.
While this approach might be thought to cause more downtime, it can lead to a reduction in downtime by efficiently utilizing smaller weather windows. For example, if you have two short weather windows in a 24-hour period, each alone insufficient for the full step but sufficient together, the Flexible option can split the step into two, utilizing both windows and avoiding a full 24-hour downtime period.
Parameters
There are 2 default parameter inputs:
- Duration: The time required to complete the step.
- Required weather window: The period of good weather (determined by the weather criteria) required to complete the step.
Speed and transit times
Transit processes have a Speed input instead of a Duration input, where you can define the cruising speed of the logistic. This value is used to determine the duration based on the distance travelled to complete the step.
You can view the average transit times to different assets given the Speed input by clicking the 3-dot overflow menu icon, then clicking Transit times.
Weather criteria
Set the weather limitations on when work can be carried out. The values you set here work with the parameter inputs to determine how long the step takes when you run the simulation.
You can choose which weather limitations are available by using the three-dot menu icon and clicking Manage limitations.