# Epicor Safety Stock and Reorder Point Calculator > Source: https://netray.co/tools/epicor-safety-stock-reorder-point-calculator > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Turn demand variability, lead time and a target service level into the safety stock and reorder point you key into Epicor Part Plant planning. ## Category epicor ## Erp Epicor Kinetic ## Industry Discrete Manufacturing ## Audience - Materials planner - Epicor administrator - Buyer ## Tool **Kind:** calculator **Inputs:** #### Average daily demand **Key:** avg_daily **Type:** number **Default:** 40 **Min:** 0 **Step:** 1 **Unit:** units/day **Help:** Mean usage per working day over the last 6 to 12 months, from part transaction history. #### Std deviation of daily demand **Key:** sigma **Type:** number **Default:** 12 **Min:** 0 **Step:** 0.5 **Unit:** units/day **Help:** Standard deviation of daily usage. Export history to Excel and use STDEV. #### Replenishment lead time **Key:** lead_time **Type:** slider **Default:** 21 **Min:** 1 **Max:** 120 **Step:** 1 **Unit:** days **Help:** Supplier lead time plus receiving and inspection, in working days. #### Target service level **Key:** service **Type:** select **Default:** 0.95 **Options:** ##### 90% **Value:** 0.9 ##### 95% **Value:** 0.95 ##### 98% **Value:** 0.98 ##### 99% **Value:** 0.99 #### Unit cost **Key:** unit_cost **Type:** number **Default:** 18.5 **Min:** 0 **Step:** 0.1 **Unit:** $ **Help:** Used only to price the safety stock investment. **Outputs:** #### Z score **Key:** z **Expr:** normsinv(service) **Format:** decimal **Description:** Standard normal deviate for the chosen service level. #### Demand during lead time **Key:** demand_lt **Expr:** avg_daily * lead_time **Format:** integer #### Safety stock **Key:** ss **Expr:** z * sigma * sqrt(lead_time) **Format:** integer **Primary:** true **Description:** Value for the Safety Stock field on Part Plant planning. #### Reorder point **Key:** rop **Expr:** demand_lt + ss **Format:** integer **Primary:** true **Description:** Lead time demand plus safety stock. #### Safety stock cover **Key:** cover **Expr:** ss / avg_daily **Format:** days #### Safety stock investment **Key:** ss_value **Expr:** ss * unit_cost **Format:** currency **Chart:** #### Safety stock and reorder point vs lead time **Type:** line **X:** lead_time **From:** 1 **To:** 60 **Steps:** 30 **Series:** - ss - rop **Currency:** $ **Disclaimer:** Assumes normally distributed daily demand and constant lead time. Lumpy or intermittent demand needs a different method. ## Content **Intro:** Safety stock is one of the most edited fields on the Epicor Part Plant planning screen, and one of the most guessed. This calculator turns your demand history, lead time and target service level into a number you can defend. Change an input and the chart shows what a longer lead time does to the investment. **Sections:** #### How to use the calculator **Body:** Pull a year of issue transactions for the part, for example from a BAQ on the part transaction table or the Part Tracker. Compute the average and standard deviation of daily usage in Excel, then enter them with the lead time you actually experience, not the number stored on the supplier record. Choose the service level the business will fund. The safety stock value is what you key into the Safety Stock field on Part Plant planning; the reorder point is useful for min/max style parts that MRP does not drive. **Bullets:** - Use working days consistently for demand and lead time - Take the standard deviation of daily demand, not of monthly demand - Recalculate after any supplier or process change #### The formula behind it **Body:** Safety stock equals Z times sigma times the square root of lead time, where Z is the normal deviate for the service level (1.65 for 95%, 2.33 for 99%) and sigma is the standard deviation of daily demand. The square root appears because variability over several independent days grows with the root of the number of days, not linearly. The reorder point is average demand over the lead time plus the safety stock. This version treats lead time as fixed; if supplier delivery varies a lot, add that variance separately. #### Reading the result and the chart **Body:** The default example shows roughly a fortnight of cover for a part with moderate variability. Move the service level from 95% to 99% and watch safety stock climb by about 40 percent: the last few points of service are expensive. The chart sweeps lead time so you can see the payoff of negotiating a shorter lead time with a supplier, which usually beats holding more stock. #### Common mistakes in Epicor planning **Body:** Planners often set a flat safety stock for every part, or leave it on after a part goes end of life. MRP treats safety stock as a demand it must always cover, so an inflated number creates suggestions that never go away. Also check the minimum, maximum and multiple order quantity fields on the same planning screen, since they interact with the reorder logic and can hide a safety stock that is too low. **Bullets:** - Do not apply this to engineer-to-order or one-off parts - Review A parts quarterly and C parts yearly - Do not include one-time spikes such as a pilot build in sigma **Cta:** If you want safety stock proposed for every active part straight from your Epicor transaction history, with the working shown, we can build that as a read-only report. **Faq:** #### Where does the safety stock go in Epicor Kinetic? **Answer:** Enter it in the Safety Stock field on the Part Plant planning tab for the part and site. MRP then plans to keep available quantity at or above that level, so check the resulting suggestions after changing a batch of parts. #### Which service level should I choose? **Answer:** Choose the level the business will pay for. 95% is a common starting point for regular parts, with 98% or 99% reserved for critical or long lead items. Each step costs more stock than the last, so compare the investment output. #### Does this work for make parts? **Answer:** Yes, if you use the replenishment lead time of the job, including queue, run and move time. Demand variability still comes from consumption history. For heavily scheduled parts, MRP and finite scheduling may matter more than safety stock. #### What if demand is intermittent? **Answer:** The normal distribution assumption breaks down for parts that sell a few times a year. Use a min/max or a bootstrap of actual history instead, and treat this result as a rough guide only. ## Search terms epicor safety stock calculation, epicor reorder point, epicor part plant safety stock, safety stock formula calculator, epicor mrp safety stock, reorder point calculator excel, epicor kinetic planning parameters --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json