A pharmacy can have full shelves and still struggle to fulfil routine demand. One product runs out while another sits behind newer deliveries. A purchase order looks sufficient until part of the shipment is delayed, or a physical count includes packs that are not available for supply.
Practical pharmacy inventory planning connects three decisions: what is genuinely available, when another order is needed, and whether the quantity can reasonably move before its usable window closes. The following workflow is designed for pharmacy buyers, stock controllers and distribution teams. Its calculations are hypothetical planning examples, not product-specific stocking recommendations.
1. Build the plan around an exact stock item
Start with a clear item record. A broad description such as “skin-care cream” is not enough for ordering or counting. Keep each brand or product, strength where applicable, dosage form, pack size and purchasing unit distinct. A carton, a retail pack and an individual unit must not share an unexplained quantity field.
For each item, maintain the following minimum planning information:
- Internal item code and complete product description.
- Purchasing unit, issue unit and any documented conversion between them.
- Usable quantity, separately identified unavailable quantity and outstanding commitments.
- Batch-level quantities and expiry dates.
- Recent demand, replenishment lead time and next confirmed delivery.
- Reorder trigger, review date and named owner.
Agree on one unit before calculating. If an order is placed in cartons of 12 retail packs, convert the demand and stock figures into retail packs first. Convert back to cartons only when preparing the order. This makes rounding visible rather than burying a twelvefold difference in the spreadsheet.
2. Separate physical stock from usable stock
A shelf count answers how many packs are present. A replenishment review needs a second answer: how many are available to meet demand? Keep blocked stock out of that figure, even when it remains in the building.
The WHO guidance on good storage and distribution practices for medical products addresses stock rotation, segregation and documented handling. It defines FEFO around the earliest expiry date and calls for returned products to be quarantined pending an appropriate decision. These principles are a useful foundation; the planning routine below does not replace approved procedures, product requirements or applicable local rules.
Use distinct status fields rather than a free-text note that the buyer may overlook. For example, record 180 packs physically present, of which 24 are on hold and 12 are already allocated. That leaves 156 usable packs before commitments and 144 uncommitted usable packs. Do not subtract the allocation again if your system already reports available stock net of commitments.
Keep pending receipts separate. An open purchase order is not stock available today. Record its remaining quantity, expected arrival and confirmation status so that a delayed shipment does not quietly conceal an immediate shortage.
3. Estimate demand without hiding stockout days
Choose a recent period that reflects the item’s normal movement, then inspect exceptions before taking an average. A one-off institutional order, a temporary promotion or a change in pack size can distort the result.
Suppose an item moved 240 packs across 30 days during which it was available. Its observed average movement is eight packs per day. If it was unavailable for several days, sales alone will understate demand. Record those days and any documented unfilled requests; do not assume that zero sales meant zero demand.
Use a consistent calendar. Daily demand based on calendar days must be paired with lead time measured in calendar days. If your operation works with trading days, use that basis throughout and account explicitly for closures.
For intermittent items, an average can obscure long gaps followed by large orders. Review the order pattern alongside the average, and consider a smaller, more frequently reviewed holding quantity. Do not infer that products with similar names or presentations can substitute for one another.
4. Calculate a reorder trigger, then check timing
A simple continuously monitored reorder point is:
Reorder point = average daily demand × replenishment lead time + safety stock.
Measure replenishment lead time from placing an actionable order to the stock becoming usable, not merely to dispatch. Include the ordinary time needed for delivery and receiving checks. Review actual completed orders rather than relying only on a quoted transit estimate.
Safety stock is an additional planning allowance for uncertainty. Its size should reflect observed variation, service needs, shelf life and operational constraints. The figure in the following example is an assumption for teaching the calculation, not a universal buffer.
Worked hypothetical example
| Planning input | Example value |
|---|---|
| Average demand | 8 packs per calendar day |
| Usable-stock replenishment lead time | 7 calendar days |
| Assumed safety stock | 24 packs |
| Reorder point | (8 × 7) + 24 = 80 packs |
| Current usable stock | 70 packs |
| Confirmed outstanding supply | 20 packs |
| Unfulfilled commitments | 10 packs |
Here, the inventory position is 70 + 20 − 10 = 80 packs. Under a policy that triggers at or below the reorder point, the item requires replenishment review now. This calculation assumes the commitments are not already deducted from usable stock and are not double-counted in the demand forecast.
Next, check the dates. If the 20 inbound packs are confirmed for day three, they may support the plan. If they are expected after the current stock would run out, the same inventory-position total is misleading. Plot expected receipts and demand by date and escalate any projected gap. A reorder formula cannot make an overdue delivery arrive sooner.
Do not confuse the trigger with the order quantity
The 80-pack trigger does not mean “order 80 packs.” Quantity needs a separate policy. For illustration, suppose the buyer chooses a target inventory position covering 21 days of average demand plus the same buffer. The target is (21 × 8) + 24 = 192 packs. Against an inventory position of 80, the provisional order is 112 packs.
If purchasing requires full cartons of 12, rounding up produces 120 packs. Before accepting that adjustment, check storage capacity, outstanding orders, batch expiry and realistic movement. The target horizon is a local planning choice, not a guarantee of availability or a recommendation for every pharmacy.
A team that checks stock only once a week should not apply a continuously monitored trigger unchanged. Its policy must account for demand between reviews as well as replenishment lead time. Whatever method is chosen, write down the review frequency so a missed check becomes visible.
5. Make expiry review part of the purchasing decision
A reorder report and an expiry report should be reviewed together. Otherwise, a buyer can replenish an item while an older batch is unlikely to move in time.
Use a batch-level view showing quantity, expiry date, location and status. Add the date by which action is needed under your procedures and any applicable customer acceptance conditions. This creates a practical review window without inventing a single minimum shelf-life rule for every product.
Consider a hypothetical batch of 90 packs with 30 days left in the operation’s permitted supply window. At an expected movement of two packs per day, only 60 packs would move during that period. The remaining 30 packs are a planning flag, not proof that demand will stay constant or that the batch can be supplied until the final day.
Assign a decision: review the forecast, reduce a pending replenishment where possible, discuss an agreed return option, or arrange another permitted action through the responsible team. Record the owner and deadline. Never treat expiry pressure as a reason to encourage inappropriate supply or bypass product restrictions.
Apply FEFO at the picking location
First-expiry, first-out means selecting the earliest-expiring eligible batch of the same item before a later-expiring batch. Receipt date alone is insufficient: a newer delivery may have an earlier expiry.
For implementation, make the batch sequence visible wherever staff pick stock. During a shelf check, compare the front picking position with the batch list. When a batch is moved, update its location. Any exception should have a documented reason under the operation’s procedures, rather than becoming an informal habit.
6. Close the loop when deliveries arrive
Give each receipt a clear owner. The ordering record should be reconciled with what was actually accepted and made available, not simply marked complete when a vehicle arrives.
A practical receiving worksheet can capture the purchase-order reference, item and pack size, delivered quantity, batch details, expiry dates, discrepancies and final status. Route concerns about identity, condition or required handling records through the appropriate authorized process before treating affected stock as usable.
For a partial delivery, leave the undelivered balance open only if it is still expected. Ask for a revised quantity and date. Otherwise, the next planner may count a “ghost” receipt that will never arrive. Record any cancellation against the same order reference.
Finally, update the actual lead-time history using the date the accepted stock became usable. A supplier delivering quickly on one occasion does not establish a new normal. Look for repeated changes before revising the planning assumption.
7. Run a short, repeatable review
A review works best when it ends with decisions rather than another exported report. Start with items projected to run out before the next usable receipt, then review expiry exposure and unresolved stock-status differences.
- Buyer: confirms order quantities, delivery dates and supplier responses.
- Stock controller: checks counts, batch locations and receiving discrepancies.
- Authorized responsible person: handles quality-status decisions and exceptions within their remit.
- Review owner: records each action, deadline and outcome.
Choose a small set of measures: stockout days, overdue purchase-order lines, quantity in expiry-review windows and unexplained count differences. Define each measure consistently. For example, an overdue line should use the current agreed delivery date while retaining earlier dates so repeated postponements remain visible.
Revisit recurring exceptions. If an item repeatedly reaches its trigger too late, examine demand, lead time and review frequency before increasing the buffer. If batches repeatedly age, examine order size and movement assumptions. More stock does not resolve every process problem.
Frequently asked questions
How often should a pharmacy review inventory?
Match the cadence to the item and its replenishment risk. Fast-moving items and delayed receipts may need daily attention, while slower items can follow a scheduled review. The chosen calculation must reflect that cadence; a weekly process needs to allow for the time until the next review.
Should quarantined packs count toward a reorder decision?
Keep them outside usable stock until an authorized decision changes their status. Show them separately so the buyer understands the physical balance without assuming that a pending release will occur. If their status changes, update the plan promptly.
Can every product use the same expiry-review threshold?
A common report can organize the workload, but one threshold may not suit every item. Consider product-specific requirements, movement, lead time and agreed acceptance conditions. Establish the relevant action window through your procedures rather than applying an unsupported universal number.
What should a replenishment enquiry include?
Send the exact item description, pack size, quantity and unit, delivery location and required timing. Ask for availability, expected delivery, relevant batch-expiry information and applicable order terms. Clear requests reduce clarification cycles and make confirmations easier to compare with the plan.
Prepare the next order with better information
Start with one manageable group of items. Reconcile usable stock, test the demand calculation, confirm outstanding receipts and review batch expiry before changing order quantities. Once the records agree, extend the same workflow to the next group.
Explore Lamed Pharmaceutical’s product categories to identify items for your enquiry. For a separate view of supplier evaluation, read the dermatology product supplier guide. When your requirement is ready, contact Lamed Pharmaceutical with the item, pack size, quantity and intended delivery timing to discuss current supply options.