Optimizing the performance and availability of an IT service in the design stage are typically considered as independent tasks. However, since both aspects are related to one another, these activities could be combined by applying performability models, in which both the performance and the availability of a service can be more accurately predicted. In this paper, a design optimization problem ...

Meyer, J.F,, Performability: a retrospective and some pointers to the future, Performance Evaluation 14 (1992) 139-156. As computing and communication systems become physically and logically more complex, their evaluation calls for continued innovation with regard to measure definition, model construction/solution, and tool development. In particular, the performance of such systems is often de...

With the increasing complexity of multiprocessor and distributed processing systems, the need to develop efficient and accurate modeling methods is evident. Fault tolerance and degradable performance of such systems has given rise to considerable interest in models for the combined evaluation of performance and reliability [l], [2]. Markov or semi-Markov reward models can be used to evaluate th...

This paper deals with object-oriented real-time dependable systems required to achieve the best usage of the resources even under adverse circumstances as transient overloads or component failures. Various possible tradeoffs among the different application requirements must be considered to allow a flexible management of system resources. On the basis of a simple formulation of the concept of o...

This paper describes how MEADEP, a system level dependability prediction tool, and CASRE, a software reliability growth prediction tool can be used together to predict system reliability (probability of failure in a given time interval), availability (proportion of time service is available), and performability (reward-weighted availability) for a. The system includes COTS hardware, COTS softwa...

The problem of computing performability probabilities in stochastic PERT and ow networks is studied when the network is \minimally designed" to withstand any two component failures. Polynomial-time algorithms to compute performability when the network is planar| the nonplanar versions being NP-hard | solve related \two-path subset" problems. Given an acyclic graph with weights on the arcs, the ...

Exactly computing network reliability and performability measures are NP-hard problems, precluding their frequent use in design of large networks. Instead, Monte Carlo simulation has been frequently used by network designers to obtain accurate estimates. This paper focuses on simulation estimation of network reliability and performability. First, a literature survey of existing approaches is gi...

This paper deals with the transient analysis of manufacturing systems in the presence of failures and repairs. The exact model is decomposed into 1) a structure state process, modeling the failure and repair events which occur at a slower time scale, and 2) a performance model, modeling the part processing and material movement events occurring at a faster time scale. The solutions of these two...

This paper proposes a vectorized measure for a set of behavioural dependability attributes. The measure is based on Markov processes and is intended for practical dependability trade-offs. It describes the system performance on a number of service levels. Thus, it is possible to merge attributes such as reliability, safety and performability into one single quality. Whereas reliability describe...