Answer to Question #109406 in Operations Research for Pk

Question

How many types of failures are considered in replacement theory?

Answer 1

1.Gradual failure: Gradual failure is progressive in nature. that is as the life of an item increases, its operational efficiency also deteriorates resulting on 1.Incresed running costs 2.Decrease in productivity 3.Decrease in the resale or salvage value.

2 Sudden failure • This type of failure occurs in items after some period of giving desired service rather than deterioration while in service.The period of giving desired service is not constant but follows some frequency distribution which may be Progressive,retrogressive or random in nature. • If the probability of failure of an item increases with the increase in its llife.tubes and light bulbs. • If the probability of failure in the beginning of the life of an item is more but as time passes the chances of its failure become less. • Failures from random causes,physical shocks,not related to age.vaccum tubes in air-borne equipment have been found to fail at a rate of the age of the tube.

 1.Replacement of items deteriorates with time • When operational efficiency of an item deteriorates with time(gradual failure),it is economical to replace the same with a new one.Besides,there could be a number of alternative choices and one may like to compare available alternatives on the basis of the running costs involved.

2. Replacement of items that fails suddenly • Uncertainty • Difficult to predict that a particular equipment will fail at a particular time • Probability of distribution of failures.

 3.Staff replacements • Related to human beings working in an organization • Applied to formulate some useful recruitment and promotion policies for the staff • We assume that life distribution for the service of staff is already known