Instructions
User has to enter the replacement cost. The replacement with a new item will define the beginning of the cycle of maintenance. During this cycle several repairs can be done with repair cost. Repair can be perfect (restoration factor q=0) or imperfect (q>0) including a case of minimal repair (q=1). User has to select the maintenance policy. They are described in General information. Then user has to enter the Weibull lifetime parameters. Note that the shape parameter should be in the interval (1, 5]. User has to enter the restoration factor q from the interval [0, 1]. Weibull parameters and restoration factor can be calculated by the Recurrent event prediction method if failure times are known.

Advanced Monte Carlo method is used in the calculation. User can select the number of Monte Carlo trials in the calculation. It is 10,000 by default. The number of trials defines the accuracy of the calculation which can be controlled by calculated standard error. The variance reduction method is used to improve the accuracy of the calculation, therefore usually 4,000 trials are enough to obtain the solution with good accuracy. It takes about 1 second. The optimal maintenance parameters for selected policy will be displayed as a result, including calculated minimal cost per unit time.