Single and small-series production companies face specific challenges, such as variable customer orderdecoupling points (CODP), decreasing quantities and rising cost pressure. This leads to a increasingproduction complexity and growing requirements on Production Planning and Control (PPC).Digitalization’s direct links between objects, people, and machines as well as detailed recording ofproduction progresses opens new solutions for PPC. However, volume of data and the required processingtimes are increasing. Thus, to achieve near-real-time data processing, a decentralization of decision-makingsystems can be observed.The function Material Requirements Planning (MRP) is PPC’s original need for Enterprise ResourcePlanning (ERP) systems. Here, PPC’s overall problem (to fulfil primary requirements for products) isdivided into subproblems (to fulfil single production orders). Especially companies characterized by anorganization in accordance to the workshop principle, high in-house production depth and variable CODPare confronted with high dynamics in their production systems. This ends in significant differences betweenprimary requirements (overall problem) and single production orders (subproblems). Ultimately, theseinsufficient PPC data result systematically in a non-optimal overall solution despite optimal partial solutions.This publication combines PPC’s fundamentals from existing commonly known models with currentimplementation concepts of ERP systems. A newly developed Low-Level-Code based Production Modelprovides explanations for deviations between the overall problem and its subproblems. Furthermore,information flows of PPC can be structured between a periodically actualized vertical and an event drivenhorizontal information flow. These recognitions lead to an improvement of PPC by ERP systems.