Ep. 40 - The Demand Planning Mistake Everyone's Making - Simon Eagle

Most companies invest heavily in forecasting, planning systems, and technology. Yet service levels still struggle, costs stay high, and planners spend their time firefighting. The problem isn't just bad forecasts - it's how those forecasts are being used.KEY CONCEPTS COVERED:- Why forecast-driven planning creates instability, cost, and inefficiency- The difference between forecast push and demand-driven pull systems- How expediting drives higher costs, longer lead times, and excess inventoryIn this episode of Chain Reaction, Michael Ostroumov is joined by Simon Eagle, a supply chain consultant specialising in demand planning and S&OP, for a practical discussion on why traditional planning approaches fail - even with advanced systems in place. Simon explains how most organisations still rely on inaccurate forecasts to drive production, leading to constant expediting, excess inventory, inflated costs, and poor service levels. He breaks down the limitations of forecast-driven planning and introduces a demand-driven alternative that aligns production with actual demand rather than predictions.This episode is particularly relevant for supply chain leaders, planners, operations teams, and anyone responsible for improving service levels, reducing inventory, and stabilising production environments.Watch this episode on YouTube: https://youtu.be/_2mFuBCwEes TIMESTAMPS:(0:00) - Introduction and guest overview(1:23) - From sales to supply chain: how Simon entered demand planning(3:50) - Why forecast accuracy alone doesn't solve planning problems(7:30) - Why companies still rely on spreadsheets despite advanced systems(9:54) - The hidden cost of expediting, changeovers, and instability(12:54) - How forecast-driven planning inflates inventory and lead times(14:59) - Traditional forecast push vs alternative planning approaches(17:40) - Why MRP and ERP systems struggle with forecast inaccuracy(20:49) - Managing spike demand and improving S&OP collaboration(23:54) - Real-world challenges with sales forecasts and volatility(27:58) - Using forecasts differently: from schedules to stock targets(31:15) - Why spreadsheets persist - and where technology fits(32:24) - Demand Driven MRP and modern planning tools(35:54) - Magic wand: what needs to change in supply chain thinkingCONNECT WITH THE HOST & GUEST:Michael Ostroumov -  https://www.linkedin.com/in/michaelostroumov/ Simon Eagle - https://www.linkedin.com/in/simoneagle/ CONNECT WITH FLOX:Website: https://www.flox.is/ LinkedIn: https://www.linkedin.com/company/flox-logistics-services/ Related Service Page: https://www.flox.is/services/marketplace/ ABOUT THIS EPISODE:In this episode, Chain Reaction explores why traditional forecast-driven planning continues to create instability in supply chains despite significant investment in systems and technology. Simon Eagle explains how forecast inaccuracy leads to expediting, increased costs, longer lead times, and excess inventory across both SMEs and large enterprises. The conversation introduces demand-driven planning as a more effective alternative, focusing on decoupling production from forecast error, improving operational stability, and aligning supply with actual demand. It also highlights the need to rethink how forecasts are used, rather than trying to endlessly improve their accuracy.#ChainReactionPodcast #SupplyChain #DemandPlanning #S&OP #Logistics