Why did Plum Living move away from Excel for inventory planning?

Excel had been flexible at the early stage of Plum Living but stopped scaling once SKU count, supplier complexity, and demand variability all rose together. Planners spent more time updating formulas and reconciling sheets across the team than analyzing exceptions. Supplier visibility flatlined because nobody had bandwidth to share rolling forecasts, and stock decisions became reactive: orders went out when shortages appeared rather than ahead of demand. The cost was paid in overstock on slow movers and stockouts on fast movers simultaneously, which is the worst possible inventory position for a DTC brand built on customer experience. Working capital climbed faster than revenue because safety stock kept being added defensively across the board, and inventory turnover deteriorated silently until cash became a real constraint on growth. Plum Living recognized the limit when the planning team's workload was scaling linearly with SKU count, which is the opposite of what an asset-light digital brand model is supposed to enable. The shift to AI-powered Supply Chain platforms was what restored operating leverage.