A computer-implemented rules based decision management system which is cross-platform, cross-industry and cross-function. The decision management system has a software architecture which includes a common code layer, a processing platform layer and a data architecture layer. The common code layer includes a common code kernel simultaneously operable on first and second hardware platforms which are different from each other, and provides software processing to interpret and apply the strategies. The processing platform layer includes a first software module supporting a processing mode for the first hardware platform, and a second software module supporting a processing mode for the second hardware platform. The data architecture layer includes a first data module supporting data storage and access by the first software module, and a second data module supporting data storage and access by the second software module.