Optimal release problems with warranty period based on a software maintenance cost model

It is of great importance to consider maintenance costs occurring during the operation phase in software development. In this paper, based on a software maintenance cost model for the testing and operation phases, the paper discusses optimal software release times which minimize the total expected software cost. Then, a development manager can quantitatively know the time when testing is terminated and the software is released to the user. In particular, the paper introduces a warranty which a contract requiring the developer to fix all software faults detected within the warranty period in the operation phase. The warranty period is assumed to obey a general probability distribution. Also, the fault detection phenomenon during the testing and operation phases is described by a software reliability growth model. [In Japanese.]