The SURE Program
(Semi-markov Unreliability Range Evaluator)

SURE is a reliability analysis program used for calculating upper and lower bounds on for the operational and death state probabilities for a large class of semi-Markov models. The program is especially suited for the analysis of fault-tolerant reconfigurable systems. The calculated bounds are close enough (usually within 5 percent of each other) for use in reliability studies of ultra-reliable computer systems. The SURE bounding theorems have algebraic solutions and are consequently computationally efficient even for large and complex systems. SURE can optionally regard a specified parameter as a variable over a range of values, enabling an automatic sensitivity analysis.

Executable Code and Source for Sun SPARCstations (SunOS) for the SURE/ASSIST programs is available in "sun_sure-assist.tar.gz". A new experimental version for PCs running Linux is also available there.

Executable Code for Linux system for the SURE/ASSIST programs is available in "Linux_sure-assist.tar.gz". A new experimental version for PCs running Linux is also available there.

A Windows version of SURE (named WinSURE) is available as public domain software. To request a copy of this program visit here. A usage agreement must be signed and mailed to NASA Langley and the software package will then be emailed to you. The program interface is described in the following Word document. It has been released as public domain. A document describing the WinSure interface is available at WinSURE_interface.doc

The following program documentation is available for SURE:

Butler, Ricky W.; and White, Allan L.: SURE Reliability Analysis: Program and Mathematics. NASA Technical Paper 2764, Mar. 1988.

Butler, Ricky W.: The SURE Reliability Analysis. NASA Technical Memorandum 87593, Feb. 1986.

Butler, Ricky W.: The Semi-Markov Unreliability Range Evaluator (SURE) Program. NASA Technical Memorandum 86261, July 1984.

Butler, Ricky W.: The SURE Approach to Reliability Analysis. IEEE Transactions on Reliability, vol. 41, no. 2, June 1992, pp. 210--218.

Butler, Ricky W.: The SURE Reliability Analysis Program. In 1986 AIAA Guidance, Navigation and Control Conference, Williamsburg, Va., Aug. 1986.

Dotson, Kelly J.: Analysis and Testing of the SURE Program. NASA Technical Paper 2817, Aug. 1988.

A detailed tutorial on modeling with ASSIST and SURE is available (postscript):

Ricky W. Butler and Sally C. Johnson, Techniques for Modeling the Reliability of Fault-Tolerant Systems With the Markov State-Space Approach , NASA RP-1348, September 1995, pp. 130

A manual describing the SURE input language is available at sure_manual.pdf

Curator: Ricky W. Butler

To parent page

Last modified: 23 July 2001