S&OP Engineering II: Demand Planning from Guessing to Probability

Your Excel says “we’ll sell 100 units.” A round, clean, deterministic number. What if you sell 120? Stockout, unhappy customer, contractual penalty. What if you sell 50? 50 units sitting in your warehouse, immobilizing capital that could be generating returns. The problem isn’t the forecast itself. It’s the arrogance of the single number. In Chapter 1 we built a “Quality Valve” that filters ERP noise. Now that we have a pure signal, we’re going to do something Excel can’t: measure uncertainty. ...

March 7, 2026 · Datalaria

S&OP: Why Your Excel Is Lying to You (and How to Interrogate It with Python)

In S&OP (Sales & Operations Planning) meetings, opinions are often discussed instead of facts. “I think we’ll sell more”, “Last month was weird”. The root problem is not the lack of business vision, it’s the lack of signal integrity. Most supply chains are managed on spreadsheets that accept anything: dates as text, blank spaces, and typos that turn a 100-unit order into 100,000. When you feed your prediction algorithm with that “garbage,” you get amplified garbage (the financial Bullwhip effect). ...

February 28, 2026 · Datalaria