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Calculate Safety Stock to Prevent Overselling in Singapore
Here’s a quick look at the main formulas we’ll be covering. Think of this as your cheat sheet for later.
Key Safety Stock Formulas At a Glance
| Formula Type | Best For | Key Inputs Required |
|---|---|---|
| Basic Rule-of-Thumb | Sellers who are new to safety stock or have relatively stable sales and reliable suppliers. A great starting point. | Max/Average Daily Sales, Max/Average Supplier Lead Time |
| Demand Variance (Z-Score) | Businesses with unpredictable customer demand but consistent supplier lead times. Perfect for trending products. | Standard Deviation of Sales, Average Lead Time, Desired Service Level (Z-score) |
| Lead Time Variability | Sellers who face unreliable supplier delivery times but have steady customer demand. Essential for managing import delays. | Average Daily Sales, Standard Deviation of Lead Time, Desired Service Level (Z-score) |
| Periodic Review Adjustments | Anyone not using a perpetual inventory system; those who review and order stock at fixed intervals (e.g., weekly). | All of the above, plus the time between your inventory reviews. |
Each of these methods solves a slightly different problem, from basic protection to fine-tuning for specific supply chain headaches. We’ll walk through exactly how to use them.