This　paper　presents　a　seamless　decision　support　system,　on　the　basis　of　a　genetic　algorithm　(GA),　for　integrating　production　planning　and　scheduling.　The　infrastructural　framework　and　the　functional　modules　in　the　proposed　system　are　described　in　detail.　An　example　is　illustrated　to　validate　the　applicability　of　the　developed　system.　The　integrated　planning　and　scheduling　decision　support　system　(IPSDSS)　was　implemented　using　VC++,　an　object　oriented　programming　language.