Reliability and Availability Investigation of Microprocessor Systems Using Markovian Approach

The primary objective of this research is to develop a stochastic model for optimizing the availability of microprocessor systems. Microprocessor is a central processing unit on a single integrated circuit that includes an input unit, terminal, processor unit, main memory unit, addressing mode unit, disk controller, and disk drives as its subsystem. There are seven subsystems of a microprocessor system. Subsystems first, second, third, and six are in single unit configuration, and subsystems four, five are configured as 2-out-of-3: G, and subsystem seven is configured as 3-out-of-4:G. Markov technique is used to generate state transition diagrams and differential equations. Reliability and availability measures of microprocessor systems are derived with respect to time for all subsystems. Runge–Kutta 4th order method is used to carry out numerical results. The rates of failure and repair are considered to be exponentially distributed. The effect of change in availability is also derived with respect to the increase and decrease in failure and repair rates simultaneously. The results are beneficial for engineers and researchers to improve the reliability of microprocessor.