Definition
MAPICS, BPCS, and System21 are ERP products with decades of history on the AS/400 and IBM i platform. MAPICS originated at IBM and ran on the System/34, 36, and 38 before AS/400, and has been owned by Infor since 2005, now marketed as Infor XA. BPCS was built by System Software Associates starting in 1981 and became Infor LX after Infor acquired SSA Global in 2006. System21 rounds out what Infor now calls its IBM i Compass Group of ERP suites.
Buyers who inherited one of these systems are often deciding between continued investment in the current platform, since Infor has continued releasing updates including planned IBM i 7.6 support and REST APIs, versus modernizing around it, versus a longer-term replacement.