Stockouts don’t just cost a sale. Instead, they erode customer trust, trigger rush fees, slow production, and wreak havoc on financial plans. And as this year’s tariff-driven stockpiling has shown, trying to “buy ahead” of disruption isn’t a reliable fix either.
According to The Wall Street Journal, many retailers padded inventory to avoid tariff-related stockouts, only to find holiday demand softening. This turned precautionary stockpiles into costly overstocks. It’s a reminder that stockouts aren’t solved by guesswork or gut feel. They’re solved by fixing the upstream planning gaps that cause them in the first place.
Let's look at five of the most common, avoidable causes — and how modern planning teams can keep stockouts from happening for good.
When demand signals are noisy, late, or modeled with static spreadsheets, inventory plans lag reality. Promotions, channel shifts, regional differences, and new-item launches all compound the challenge.
Business Insider reports that companies like Walmart and Target are adopting AI-driven forecasting specifically to prevent inventory gaps caused by outdated prediction methods.
How to fix it
You can’t plan what you can’t see. If supplier reliability, open POs, production capacity, and in-transit inventory aren’t visible in one place, planners end up making decisions with stale or disconnected data.
A Supply Chain Dive analysis highlighted this exact problem: retail teams often operate with fragmented data systems, leading to mismatched inventory records, inaccurate replenishment triggers, and slow responses to supply variability.
How to fix it
Static lead times and “set-and-forget” safety stock policies are two of the most common root causes of stockouts — and overstock.
The WSJ’s reporting on tariff-driven stockpiling illustrates this perfectly. Retailers made large buys based on assumed lead times, demand expectations, and outdated buffers. Later, they found those assumptions didn't align with reality. When the input math is wrong, the output plan will be wrong.
Industry experts reinforce this point. ASCM explains that safety stock is designed specifically to protect companies from forecast errors and fluctuations in both demand and supply. But it only works when safety stock is calculated intentionally — using real variability, not rules of thumb or outdated parameters.
How to fix it
If replenishment happens only after inventory hits a warning threshold, you’re already behind. Reactive planning creates avoidable expedite fees, last-minute supplier scrambling, and frustrated customers.
Business Insider reports that major retailers are investing heavily in predictive tools — not because it’s trendy, but because reactive planning is too slow for today’s volatility. AI is helping these teams model disruptions in advance, allocate inventory more strategically, and respond before shortages occur.
How to fix it
Sales over-commits. Operations underestimate capacity. Finance tightens budgets. Without a shared plan, stockouts become almost inevitable.
Supply Chain Dive’s reporting on retail data alignment reinforces this: disconnected teams using different data definitions and separate systems often drive conflicting decisions, creating delays and shortages.
How to fix it
Stockouts aren’t bad luck. They’re a signal that your planning process, data quality, or cross-team alignment needs an upgrade. Companies that connect demand, supply, and operations — while giving planners the right models, visibility, and alerts — consistently reduce stockouts and the costs that come with them.
TransImpact helps teams: