Software maintenance: the need for standardization

Procedures are proposed to assist the Navy Management Systems Support Office in performing software maintenance. Hardware and software maintenance are contrasted. The key difference between the two -- the ease which software can be changed -- leads to the need for managing software change. Standardization of software is proposed as the method for managing software change. A model of software maintenance is advanced as the function for standardizing software maintenance. (kr)Prepared for: Navy Management Systems Support Office, Norfolk, VAhttp://archive.org/details/softwaremaintenanc00schnApproved for public release; distribution is unlimited

The state of software maintenance

A state of software maintenance survey is presented, indicating the incongruity of the simultaneous existence of important and neglect in this field. An overview is given of selected developments and activities covering the following topics: the "Maintenance Problem", models, methods for improving maintenance, metrics, maintenance information management, standards, maintenance of existing code, and surveys. The paper concludes with a prognosis of what is ahead in maintenance: a battle and tradeoff between the forces for maintaining the base of existing software and the forces for the evolution of new systems. An Appendix is provided for the reader who desires information about a software maintenance conference and a special interest group

An approach to software reliability prediction and quality control

December 5-7, 1972, Fall Joint Computer ConferenceThe increase in importance of software in command and control and other complex systems has not been accompanied by commensurate progress in the develop- ment of analytical techniques for the measurement of software quality and the prediction of software reliability. This paper presents a rationale for imple- menting software reliability programs; defines software reliability; and describes some of the problems of performing software reliability analysis. A software reliability program is outlined and a methodology for reliability prediction and quality control is presented. The results of initial efforts to develop a software reliability methodology at the Naval Electronics Laboratory Center are reported

Computer System Testing

Increasingly, the quantitative evaluation of computer software is recognized as critically important to the effective functioning of computer systems. At NPS, the model for statistically analyzing software error detection and correction processes during software functional testing has been developed. The model provides decision aids for controlling the quality ofcommand and control system software. The inputs to the model are error detection histories and the outputs are forecasts of the future behavior of error detection and correction processes

Analysis of computer performance in multiprogrammed processing

An analysis was made of the correlation between performance and resource usage variables of a given computer job and between the performance variables of a given job and the resource usage variables of other jobs in a multiprogramming environment. This analysis was performed in order to: (1) determine the mix and characteristics of jobs which lead to high performance, (2) provide regression equation predictors of performance for given resource utilizations, and (3) provide performance and resource utilization coefficients for use in a linear programming resource allocation model. The linear programming model is used to select an optimum job mix subject to production, resource usage and budgetary constraints. (Author)Nava1 Weapons Center, China Lake, Californiahttp://archive.org/details/analysisofcomput00schnN60530 72PO-2-0056N

Predicting Deviations in Software Quality by Using Relative Critical Value Deviation Metrics

Abstract We develop a new metric, Relative Critical Value Deviation (RCVD

The first T cell response to transmitted/founder virus contributes to the control of acute viremia in HIV-1 infection

Identification of the transmitted/founder virus makes possible, for the first time, a genome-wide analysis of host immune responses against the infecting HIV-1 proteome. A complete dissection was made of the primary HIV-1–specific T cell response induced in three acutely infected patients. Cellular assays, together with new algorithms which identify sites of positive selection in the virus genome, showed that primary HIV-1–specific T cells rapidly select escape mutations concurrent with falling virus load in acute infection. Kinetic analysis and mathematical modeling of virus immune escape showed that the contribution of CD8 T cell–mediated killing of productively infected cells was earlier and much greater than previously recognized and that it contributed to the initial decline of plasma virus in acute infection. After virus escape, these first T cell responses often rapidly waned, leaving or being succeeded by T cell responses to epitopes which escaped more slowly or were invariant. These latter responses are likely to be important in maintaining the already established virus set point. In addition to mutations selected by T cells, there were other selected regions that accrued mutations more gradually but were not associated with a T cell response. These included clusters of mutations in envelope that were targeted by NAbs, a few isolated sites that reverted to the consensus sequence, and bystander mutations in linkage with T cell–driven escape

A System Response Time Model for Local Area Networks

The article of record as published may be located at http://dx.doi.org/10.1109/FTDCS.1992.217469There are several issues that confront LAN management with respect to allocating servers and files in a LAN. These are: How many servers should be used for a given number of user computers? Should files be replicated on the servers to provide better performance or should the available servers store different files in order to maximize the number and variety of programs on the, LAN? What should be the acceptable access times for users, singly and simultaneously, to access an application program, with a given number of servers and user computers? These issues are analyzed as a problem in optimization to determine the optimal server/user computer ratios and degree of file replication for given access times. Analytical and empirical results are reported