Performability measures are often defined for analyzing the worth of fault-tolerant systems whose performance is gracefully degradable. Accordingly, performability evaluation is inherently well-suited for application of reward model solution techniques. On the other hand, the complexity of performability evaluation for solving engineering problems may prevent us from utilizing those techniques ...

A new performance and performability modeling tool is introduced in this paper. PENE-LOPE is the rst tool which incorporates evaluation and optimization algorithms. It is the result of a combination between the performability modeling concept and Markov decision theory. Diierent algorithms are adopted and included in the tool under the unifying paradigm of reconngurability as the basis for adap...

In this paper, we discuss issues in performability modeling of \software rejuvenation," a form of software fault tolerance based on occasionally cleaning up the operational environment. System factors which play a key role in such a model are identi ed. Among these, we comment on two issues of particular interest when modeling software rejuvenation: (1) the representation of the degradation in ...

De Souza e Silva, E. and H.R. Gail, Performability analysis of computer systems: from model specification to solution, Performance Evaluation 14 (1992) 157-196. Computer systems reliability/availability modeling deals with the representation of changes in the structure of the system being modeled, which are generally due to faults, and how such changes affect the availability of the system. On ...

Uncrewed Aerial Vehicles (UAVs) have been used in mission-critical scenarios such as Search and Rescue (SAR) missions. In a scenario, flight autonomy is key performance metric that quantifies how long the UAV can continue with given battery charge. running multiple software applications, also be impacted by faulty application processes excessively consume energy. this paper, we propose FA-Assur...

PMCCS-6 The Sixth International Workshop on Performability Modeling of Computer and Communication Systems September 5-7, 2003 Monticello, Illinois, USA part of the 2003 Illinois International Multiconference on Measurement, Modelling, and Evaluation of Computer-Communication Systems Extended Abstracts PMCCS-6 The Sixth International Workshop on Performability Modeling of Computer and Communicat...

When making an engineering design decision, it is often necessary to consider its implications on both system performance and dependability. In this paper, we present a performability study that analyzes the guarded operation duration for onboard software upgrading. In particular, we define a “performability index” Y that quantifies the extent to which the guarded operation with a duration φ re...

Stochastic activity networks have been used since the mid1980s for performance, dependability, and performability evaluation. They have been used as a modeling formalism in three modeling tools (METASAN, UltraSAN, and Möbius), and have been used to evaluate a wide range of systems. This chapter provides the formal definitions and basic concepts associated with SANs, explaining their behavior an...

Duke University, Durham Petri-net based models have been extensively used for performance & performability modeling to analyze computer & communication systems [ 1 71. However, in the dependability modeling co-unity, Petri-net based models have received co~i&rably less attention [8 101. This paper describes a methodology to con

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...