The performance analysis of any multiple pulse position modulation (PPM) system is extremely time consuming because of the effects of different detection errors on the multiple PPM alphabet. In a small multiple PPM system such as (122), there are 64 codewords and each one can have ten possible false alarms, two possible erasures and four possible wrong-slot errors. The situation is worse if higher-order codes are considered. A novel algorithm, which reduces the time taken to predict the sensitivity of a multiple PPM system from almost 2h of analysis to under a second, is presented. Results obtained using this method agree with those obtained using a full mathematical model. The authors also present a methodology that obtains a close to optimum mapping for any multiple PPM system. Detailed results show the effectiveness of this mapping routine.