The Performance Meter

Unlike other simulation and optimization models, Patchworks does not run through a series of steps and terminate with an 'optimal' outcome. Patchworks can be used to explore a range of treatment options, and remains active until you are finished. As the scheduler executes, it searches the solution space testing various treatment timing configurations. The quality of the solution gradually improves as the various objective function values are satisfied. The scheduler does not come to a stopping point however, it instead continues to search for marginal improvements to the schedule and the objective function. Over time the value of the solution will converge towards the optimum value (for a given set of targets). You can monitor the progress of the scheduler using the "Performance meter". The meter is located on the new "Performance" panel, located in the bottom left-hand corner of the main Patchworks window.. This meter displays red when the scheduler is actively improving the solution, turns yellow when the solution begins to converge, and green when the scheduler can find no better solution. In general, there will be very little further improvement to the objective function once the performance meter has stopped showing red. If you change the target values after the solution has converged, the scheduler will immediately begin to seek the new optimum solution by changing the treatment schedule. Typically the performance meter will once again turn red as solution starts to change. The red/yellow/green strip chart indicates the number of performance improving changes that the model is making at each time step. When the number of improvements dwindles (there are fewer improvements to be found) the colour turns green.