Indicates whether to optimize maintenance intervals locally. When this checkbox is cleared (default), intervals are not optimized locally. When this checkbox is selected, intervals are optimized locally. This means that an interval for a task in optimized in respect only to the block and its calculation properties. Under Optimization target, Goal becomes available so that you can specify your optimization objective.

When clicked, the Maintenance Intervals Optimization Parameters window opens so that you can view and modify the values to use to calculate optimal intervals for maintenance tasks inserted in the Calculation Properties windows for blocks. For more information, see Maintenance Interval Optimization Parameters window. This link appears to the right of the checkboxes for optimizing intervals locally and globally.

Indicates whether to optimize maintenance intervals globally. When this checkbox is cleared (default), intervals are not optimized globally. When this checkbox is selected, intervals are optimized globally. This means that an interval for a task is optimized in respect to the entire diagram. Under Optimization target, Goal and many other properties become available.

The optimal repair resource value is the number of repair resources that minimizes or maximizes a specified objective function, which is referred to as the goal. If the goal is to minimize total cost, then the optimal value represents the number of repair resources that minimizes total cost. The optimal number is calculated using optimization algorithms integrated within the Monte Carlo simulation engine. When calculating optimal values, the values used are those specified in the Repair Resource Optimization Parameters window and the optimization targets specified beneath Optimization target. When this checkbox is cleared (default), repair resource optimizations are not performed. When it is selected, repair resource optimizations are performed.

When clicked, the Repair Resource Optimization Parameters window opens so that you can view and modify the values to use to calculate optimal quantities for any or all repair resources inserted in the Project’s RBD Repair Resource file. For more information, see Repair Resource Optimization Parameters window.

The optimal number of spares value is the number of spares that minimizes or maximizes a specified objective function, which is referred to as the goal. If the goal is to minimize total cost, then the optimal value represents the number that minimizes total cost. Similarly, if the goal is to maximize mean availability, then the optimal value represents the number that maximizes mean availability. The optimal number of spares is calculated by evaluating the function specified as the goal with a varying number of spares. For example, if the goal is to minimize total cost, the total cost for a different number of spares is calculated. The optimal number corresponds to the minimum value of the total cost. When calculating optimal values for the number of onsite spares, offsite spares, and/or replenishment levels, the values used are those specified in the Repair Spares Optimization Parameters window and the optimization targets specified beneath Optimization target. When this checkbox is cleared (default), spare optimizations are not performed. When it is selected, spare optimizations are performed.

When clicked, the Spares Optimization Parameters window opens so that you can view and modify the values to use to calculate optimal spare and replenishment quantities for all spares pools inserted in the Project’s RBD Spares Pool Resource file. For more information, see Spares Optimization Parameters Window.

The goal to use when performing optimizations. Choices are Maximize Mean Capacity, Maximize Mean Availability, Maximize Reliability, and Minimize Total Cost. The default is Minimize Total Cost. For example, if you select Minimize Total Cost as the goal, for spares optimizations, no spare is added if the cost of adding the spare exceeds the cost saved by increasing the system availability when other desired constraints are met. The selection you make for this property determines the availability of some of the other properties in this area.

The time at which to calculate results. Choices are:

Indicates whether to calculate results for desired or average capacity. For more information, see Capacity Calculations. This property is available only when total system cost is minimized. Choices are:

The minimum desired availability of the system. This property is available only when the goal is to minimize total cost.

Desired capacity OR Average capacity

The minimum desired or average capacity of the system, depending on the one for which results are calculated. The actual capacity of the system is specified on the General page. The required capacity is used to calculate downtime costs. This property is not available if the goal is to maximize mean capacity.

The maximum number of iterations allowed for the spares optimization algorithm. Note that during each iteration, only one additional spare is assigned for the entire diagram. Overall, the maximum number of iterations specified here limits the maximum total number of spares that can be added.

Spending limitations placed on spares. This property is available only when Optimize spares is selected. The value entered in this field applies to the number of spares that the optimization places in the spares pool at the start of the simulation (at time zero). It does not apply to spares that are bought later as a result of replenishment or emergency orders. You can use this field to specify space constraints based on weight or volume. For example, the number of spares carried on board an aircraft might be limited by weight. In this case, you specify the weight or volume of the individual component as its cost.