Outputs between C1 and C3 should be comparable, but you might see small discrepancies.

This page provides an overview of some of the changes between C1 and C3 that might impact your case outputs, so you can understand why you’re seeing discrepancies and take steps to mitigate them.

Weather

  • Weather file overlap:
    • C1: When using multiple weather files (e.g., one at a base, another for your WTGs), the engine only uses the overlapping years.
    • C3: The engine uses the full weather files regardless of overlap to remove limitations involved in using multiple weather files without overlapping data.
    • Result: A C1 case might use fewer years of weather data or at least different years of the data than a C3 case using the same weather data file.
  • Increment start year ordering:
    • C1: Moves through the weather file years in ascending order, e.g., 2020, 2021, 2022, then 2023.
    • C3: Descending order from the most recent year in the file.
    • Result: If you run a case with fewer simulation years that weather years, the simulations in C1 and C3 will run over different weather years.
  • Partial weather years:
    • C3: The engine only considers full years in the weather file. Remove the last year from your weather data file if it is a partial year.

Logistic processes

  • Time between steps:
    • C1: The engine plans each step individually, resulting in small time periods between steps where the engine checked for the next steps.
    • C3: Schedules a full process in one chunk, so you don't see additional time between steps.
    • Result: C1 logistic processes might be slightly longer.
  • Arrival at base/demobilization:
    • In the cycle (C1) and processes (C3) tabs, the Arrival at base cycle in C1 has become the Demobilization process in C3. Likewise, Transit from wind farm (C1) has become Transit to port(C3).
    • Make sure to carry over the relevant inputs and weather criteria from one to the other.

Outputs

  • S-Curve:
    • C1: S-Curve used the nearest-rank method to display data.
    • C3: S-Curve displays data from a single p run.

Transfer vessels and commissioning tasks

The algorithm for assigning work to personnel and vessels underwent significant changes between C1 and C3. You can expect to see changes in outputs related to these two factors.


One of the most notable examples is, in C3, personnel are always returned to base in time for their work shift end time. In C1, personnel would sometimes be returned to base after their work shift had ended.