This note addresses the production and maintenance control problem of a fai
lure prone manufacturing system consisting of one machine and producing one
part type. The machine is assumed to have three working states: good, aver
age and bad, and a failure state. In the three working states, the machine
can produce parts and some of these parts are rejected with a rate dependin
g on the machine state. In the failure state, no part is produced. The stat
e transition of the machine is governed by a continuous-time Markov process
. The jump rates from average and bad states to the good state are the prev
entive maintenance rates and the one from failure state to good state is th
e corrective maintenance rate. The production rate and the maintenance rate
s are optimized.