Why is your team still using Excel to forecast?

Key ideas

• Teams export from million-dollar systems into spreadsheets because the platform is not giving them the flexibility, transparency or trust the month requires. The question is what the system is failing to deliver, not why planners are "going rogue."
• One-size-fits-all models bake in generic assumptions. Grocery, apparel and intermittent-demand categories need different treatment; a single cold run across 30,000 series cannot respect that heterogeneity.
• Prophet and NeuralProphet were designed to be interactive and inspectable, not batch-processed blindly at scale. The valuable workflow is explore, adjust, and learn, not accept a black-box number.
• Human adjustments to forecasts are accurate typically if they are large and downward.
• LLMs are for language and reasoning, not numerics. Use them to capture messy context and explain assumptions; leave the math to proven forecasting and optimization methods.
• The durable pattern is a governed system of record plus a flexible, learnable decision layer on top, where overrides are visible, attributable and improve the next cycle.