A method for determining an optimal auto-save time for a word processor

The present study proposes a method for determining an optimal auto-save time for a word processor which has a relatively large CPU memory. Under the proposed method, a document file on the CPU memory is auto-saved on a hard disk or a floppy disk at time T,2T,3T,.... The system availability of the above method is formulated as an objective function to be maximized. For a system subject to exponential failures, it is shown that there always exists an optimal value T*. A numerical example is also presented to show the theoretical underpinnings of the proposed method.