A second version of the Availability, Cost and Resource Allocation (ACARA) computer program has become available. The first version was reported in "System-Availability and Resource- Allocation Program" (LEW-15713), NASA Tech Briefs, Vol. 19, No. 8 (August 1995), page 54. To recapitulate: ACARA analyzes the availability, mean-time-between- failures of components, life-cycle costs, and scheduling of resources of a complex system of equipment. ACARA uses a statistical Monte Carlo method to simulate the failure and repair of components while complying with user-specified constraints on spare parts and resources. ACARA evaluates the performance of the system on the basis of a mathematical model developed from a block-diagram representation. The previous version utilized the MS-DOS operating system and could not be run by use of the most recent versions of the Windows operating system. The current version incorporates the algorithms of the previous version but is compatible with Windows and utilizes menus and a file-management approach typical of Windows-based software.

This program was written by Larry Viterna and Dale Stalnaker of Glenn Research Center.

Inquiries concerning rights for the commercial use of this invention should be addressed to

NASA Glenn Research Center
Commercial Technology Office
Attn: Steve Fedor
Mail Stop 4–8
21000 Brookpark Road
Cleveland
Ohio 44135.

Refer to LEW-17308.


NASA Tech Briefs Magazine

This article first appeared in the February, 2004 issue of NASA Tech Briefs Magazine.

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