We model a gracefully degrading mul-tiprocessor soft real-time system which is subject to both dynamic (software) and static (hardware) failures, without recovery, using a Markov process. We derive the traditional reliability performance measure and meantime to failure (MTTF) of such a system with respect to both failure types and introduce a parameter, expected-deadline-missed, which is the ex...

Degradation analysis is used to analyze the useful lifetimes of systems, their failure rates, and various other system parameters like mean time to failure (MTTF), mean time between failures (MTBF), and the system failure rate (SFR). In many systems, certain possible parallel paths of execution that have greater chances of success are preferred over others. Thus we introduce here the concept of...

Designing highly dependable systems requires a good understanding of failure characteristics. Unfortunately, little raw data on failures in large IT installations is publicly available. This paper analyzes failure data recently made publicy available by one of the largest high-performance computing sites. The data has been collected over the past 9 years at Los Alamos National Laboratory and in...

The reliability of software is one of the most important software metrics. In the course of time, systems have become more and more complex and that is why software has become more complex, too. It is an undeniable fact that this will lead to an increasing number of software faults. Models of software reliability are used to track down software faults. The aim is to make sure that an improvemen...

Recent investigations into resilience of large-scale highperformance computing (HPC) systems showed a continuous trend of decreasing reliability and availability. Newly installed systems have a lower mean-time to failure (MTTF) and a higher mean-time to recover (MTTR) than their predecessors. Modular redundancy is being used in many mission critical systems today to provide for resilience, such...

Abstract: This paper presents a mathematical model for a multi-state complex repairable manufacturing system with four types of failures such as common cause, partial, human and catastrophic incorporating waiting time to repair. As regards to repairing of the system, it has to be wait for repair due to unavailability of repair facility after common cause failure. The system may also fail due to...

Un-availability can be quantitatively defined as the ratio of MTTR (mean time to repair) to the sum of MTTR (mean time to repair) and MTTF (mean time to failure). Decreasing MTTR is as valuable as increasing MTTF. By learning why systems fail, failure distribution across parts of an IS, we attempt to envision a plausible model for future Information Technology (IT). In this endeavor, we focus o...

Increasing MTTF requires increasing reliability. In previous lectures we saw a variety of ways to do so: testing, static analysis, formal methods, etc. A highly reliable system is a highly available system. Reducing MTTR requires reducing the (mean) time it takes for the system to come back up once a failure has occurred. Once a failure occurs, we must detect it, diagnose it, and the recover th...

MTBF (mean time between failures) is the expected time between two successive failures of a system. Therefore, MTBF is a key reliability metric for systems that can be repaired or restored. MTTF (mean time to failure) is the expected time to failure of a system. Non-repairable systems can fail only once. Therefore, for a non-repairable system, MTTF is equivalent to the mean of its failure time ...

In recent times in the business of semiconductor testing, the claim has been that Test Cost has begun to dominate the overall cost of product (die + packaging + test) in some product lines. The cost models that I have seen are simplistic models that just take into account the product yield and the per-second test cost. More recently, I have become even more concerned over the effects of Mean-Ti...