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By David Sweetman, Senior Marketing Director – SAP S/4HANA Digital Supply Chain


MRP at its core hasn’t changed much since it came in to being in the 1960’s. It drastically improved the reliability of supply, optimized production and provided huge benefits in reduced inventory and optimized capacity.  At its heart was the principle of evaluating demand forecasts balanced with actual demand, against available product.   It would time phase the distribution, manufacturing, and procurement to meet that demand.     Safety stock inventory was set up to mitigate against the variability of demand and the inaccuracy of our forecasts.


In the early days,  supply chains were less complex, less volatile and with longer product life cycles , so MRP was more than adequate.    In today’s world, classic MRP has issues:   it relies on the assumption of forecast accuracy,  and the concept of the bill of materials to propagate dependent demand,   which often leads to the “bull whip effect”,  high inventories, and service challenges.


The “new normal” challenges of complexity and volatility in the supply chain challenge the assumptions of classic MRP.      Happily, a new approach has emerged:   Demand Driven MRP

Supply chain characteristics Before Digitization In the Digital Age
Supply Chain Complexity Low High
Product Life Cycles Long Short
Customer Tolerance times Long Short
Product Complexity Low High
Product Customization Low High
Product Variety Low High
Lead time Parts Few Many
Forecast Accuracy High Low
Pressure for Leaner Inventories Low High
Traction Friction High Low



Today our world is characterized by high customer expectations,  customizable products,  global competition,  and distributed, long-lead-time supply networks.   In such a world, the assumption of forecast accuracy is challenged,  and the approach of using safety stock to mitigate variability leads to imbalanced stocks,  with many SKUs with too much inventory,   many SKUS with too little,  resulting in the worst of both worlds:   high stocks in conjunction with inadequate service.


DDMRP offers a different approach:    by strategically locating inventory buffers at “decoupling points”  and focusing replenishments on true demand,  we limit the bullwhip effect.     These inventory buffers are then dynamically adjusted to reflect the actual demand and lead times that we are experiencing.     Buffers are monitored and managed using a simple visual process,  and orders are prioritized according to the status of the buffer,   not according to the MRP due date.


SAP has been a supporter of the Demand Driven Operating Model for some time, and has been engaged with the Demand Driven Institute, along with many of our customers to drive this new approach. SAP now delivers DDMRP, both in the cloud-based Integrated Business Planning environment (IBP), as well as in S/4 HANA, SAP’s next generation ERP solution.  The solution is jointly offered with our partner, Camelot ITlab.   DDMRP running on S/4HANA is a comprehensive approach, spanning planning and execution,  which will deliver significant improvements to customer service, working capital, and overall responsiveness.


I’d encourage you to learn more about DDMRP and see if it makes sense for your business, a wealth of materials is available at:


An Executive overview of DDMRP


The precisely wrong video (an explanation of DDMRP)


The SAP DDMRP Strategy Blog


DDMRP Institute

You can also email for further questions

David is the SAP senior marketing director of SAP S4/HANA Digital Supply Chain.