Our Software —


Optimal Replacement of Equipment in the Short Term

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OREST software is designed to help managers analyze their reliability data and obtain optimal replacement policies based on the data available. Using information about components; failure and suspension event information; and operating cost functions for components, OREST can execute Trend Analysis of failure data, and Weibull Analysis, and then obtain the optimal preventive replacement policy.

OREST will also identify the optimal change-out time for components that do not unexpectedly fail, but result in a decreasing level of performance as they age.


  1. Components-age, cost, number in service, planning horizon, preventive and failure replacement costs

  2. Event Data-type (failure or suspension), frequency, age

  3. Operating Cost-operating cost at each age interval


OREST software will enable you to establish the optimal preventive replacement age in two scenarios:

  1. Deterministic Preventive

    • Replacement Balance the operating cost and the replacement cost per unit time to minimize total cost per unit time for the life cycle of an item that has an increasing operating cost per unit time

  2. Age Preventive Replacement

    • Trend analysis to test if the failure process of a item has one of the following trends: reliability growth, reliability deterioration, no reliability trend

    • Weibull analysis to determine the shape parameter of the failure distribution

    • Establish optimal change-out time of an item through balancing the preventive replacement cost and the failure replacement cost to minimize expected total cost per unit time