This paper deals with a modularly redundant system with many active units and a warm standby unit. The concepts of 'coverage' and 'manual recovery' have been incorporated. Probabilities that the system can recover automatically/manually at the time of failure of an active unit, are fixed. Failure time distributions of an active and standby units are exponential with different rates. However, distributions of time to repair a failed unit, recovery device, time to manual recovery pre taken as general. It is assumed that the system earns a fixed amount for the duration it is operative and repair cost is incurred when a unit/RD is under repair. Expected profit of the system has been obtained by superimposing Howard's reward structure on the semi-Markov process generated by the system model. System performance (expected profit) has been studied for its behaviour. Several earlier well known models are included as special cases.