Pausing Uncertainty Runs 

Prior to OSCAM Ship v8.4 it was not possible to see uncertainty results until a run had completed. If performing a long run of 5000+ replications it is often useful to review the results after a few hundred replications to check that results for all of the CAPE elements look feasible and that sensible probability distributions have been selected. Previously the run would be stopped early to review the results but then the uncertainty run would be started from the beginning and these initial replications would be lost.

In OSCAM Ship v8.4 it is possible to pause an uncertainty run to review the results and then continue the run from that point. During a pause the uncertainty input definitions cannot be changed, but for runs without correlation it is possible to change the number of replications so that these can be increased if the standard error is too large for the required decision making.

When a run is started, the run button on the uncertainty control panel will change to a pause button. If the pause button is clicked then the uncertainty results screen will be displayed. It is then possible to return to Uncertainty Input Form and resume the uncertainty run. Other inputs sectors can also be viewed during a paused uncertainty run, however, any editing of input data, loading a different data record, or performing a standard simulation run or Sensitivty Analysis run will stop the uncertainty run.

Uncertainty control panel during a run

Uncertainty control panel showing the Preview Input Data Samples button  

During a pause it will not be possible to edit uncertainty inputs. Other options may be available depending on whether or not the uncertainty input definitions contain correlation:

When any correlation is defined the sample data is all generated before the first replication. The Review Input Data Samples button will allow the full set of data samples to be viewed for the number of replications specified in the Replications input box. It will not be possible to extend the number of replications for the uncertainty run since the sample data with the required degree of correlation has already been generated.

When no correlation is defined then data sampling is done before each replication for that replication only, so the sample data will build up during an uncertainty run. The Review Input Data Samples button will allow sample data to be viewed for the replications to date (before a run starts, the Preview Input Data Samples button shows all sample data the number of replications specified in the replications edit box). During a pause it is possible to edit the number of replications specified in the Replications input box, and the Pause checkbox will be enabled which will pause the uncertainty run when the specified number of replications is reached, rather than stopping it, so that the number of replications can be increased at that point if required.

During a pause the resume button will be displayed, which allows the uncertainty run to continue, or the stop button can be used to halt the uncertainty run.

Uncertainty control panel during a pause when no correlation is defined

Uncertainty control panel during a pause when no correlation is defined