Stochastic Markov process is formulated for a system of independent production machines with few redundant units in cold, warm or hot standby regime. The disposable repair capacity is restricted. Resulting system of Kolmogorov-Chapman differential equations is solved numerically for different of the production system. Time evolution is relatively insensitive on the renewal capacity and the number of redundant units. The steady state is completely determined by the ratio of failure and the repair rate. Effectiveness of the system as measured by the volume of production is markedly influenced also by such factors like the renewal capacity and the number of redundant units.