Availability Allocation of Networked Systems Using Markov Model and Heuristics Algorithm

Abstract

It is a common practice to allocate the system availability goal to reliability and maintainability goals of components in the early design phase. However, the networked system availability is difficult to be allocated due to its complex topology and multiple down states. To solve these problems, a practical availability allocation method is proposed. Network reliability algebraic methods are used to derive the availability expression of the networked topology on the system level, and Markov model is introduced to determine that on the component level. A heuristic algorithm is proposed to obtain the reliability and maintainability allocation values of components. The principles applied in the AGREE reliability allocation method, proposed by the Advisory Group on Reliability of Electronic Equipment, and failure rate-based maintainability allocation method persist in our allocation method. A series system is used to verify the new algorithm, and the result shows that the allocation based on the heuristic algorithm is quite accurate compared to the traditional one. Moreover, our case study of a signaling system number 7 shows that the proposed allocation method is quite efficient for networked systems.

Research on the Reliability Allocation Method for a Production System Based on Availability

“…By substituting the obtained steady-state availability into (19), the stable availability of the system is A � 1 − ( 4 i�1 (1 − A i ′ )) � 0.9925. If the expected availability is increased to 0.9999, the estimated availability assigned to each workstation is calculated according to equations (28) and (29), and the specific values are shown in Table 4.…”

“…ese factors make the working state of the production system appear polymorphic. For a multistate system, the Markov model [19], a Bayesian network [20,21], a fuzzy mathematical method [8,22], and other methods are currently used. e Markov model is used to construct the reliability model by dynamically describing the system state and the transition of the state from two aspects of the system.…”

Optimal availability improvement for digital switching systems

“…As multiple down states (e.g., caused by detection failure, coverage failure, diagnostic failure, recovery failure, etc.) exist in a networked systems, Li et al [10] apply network reliability algebraic methods and Markov model to derive the availability expressions on the system level and component level, respectively. A heuristics algorithm is proposed to allocate the network availability based on the principles of the original AGREE reliability allocation method (developed by the Advisory Group on Reliability of Electronic Equipment) and the failure-rate-based maintainability allocation method.…”