Build a stock lens assortment from your own demand, supply constraints and service targets rather than a generic power distribution. Track each confirmed specification separately and distinguish routinely stocked combinations from jobs routed to RX supply. A useful plan makes both shortages and slow-moving stock visible before the next order.
Key takeaways
- Use actual demand by SKU, including recorded lost orders.
- Separate on-hand, incoming and committed quantities.
- Review replenishment assumptions when lead times or demand change.
Define the unit you are planning
A SKU should identify the lens combination that your warehouse and sales team actually distinguish: material, design, diameter, coating and power as appropriate. Keep that identity consistent from ordering to receiving. GS1's traceability framework offers background on stable identification and linked records.
Do not aggregate two products merely because their sphere and cylinder match. If customers require different coatings or diameters, combining them can make total inventory look healthy while one specific item remains unavailable.
Reference: GS1: Global Traceability Standard
Use a planning sheet with visible assumptions
The following columns help explain why a reorder is proposed. They are a practical planning model, not a universal stocking formula or a recommended service level.
| Input | What to record | Review question |
|---|---|---|
| Demand | Sales, qualified requests and known lost orders | Does recorded sales understate demand during stockouts? |
| Inventory | Usable on-hand, commitments and confirmed incoming stock | How much is actually available to sell? |
| Supply | Confirmed availability and observed replenishment time | Have delays or minimum quantities changed? |
| Decision | Reorder amount and documented rationale | Does the order create excess in slow-moving cells? |
Work through one transparent example
Suppose an illustrative SKU receives 30 pieces of demand per month and replenishment takes two months. The simple demand during that interval is 60 pieces before any separately chosen buffer. If there are 40 usable pieces on hand, 20 confirmed incoming and 10 already committed, the simplified available inventory position is 50 pieces.
That comparison exposes a 10-piece gap before a buffer, but it is not automatically the purchase quantity. Review incoming timing, demand variability, minimum order rules and the service target. State your assumptions so a colleague can challenge them instead of hiding them inside a spreadsheet formula.
- Use one time unit for demand and lead time.
- Exclude damaged or quarantined stock from usable quantity.
- Avoid counting the same incoming order twice.
- Separate a deliberate buffer from expected demand.
Create a review rhythm and an RX route
Review fast-moving and slow-moving combinations separately. For a low-demand item, a clear RX or special-order route may be more appropriate than repeatedly buying a large minimum quantity. Confirm the service implications before promising availability to customers.
Compare each reorder decision with later demand and actual delivery. Record whether a shortage came from forecast error, supplier delay, an incorrect SKU or a receiving discrepancy. That explanation helps improve the next assortment instead of responding to every issue by increasing all stock levels.
Buyer questions
Frequently asked questions
Is there a standard power mix every wholesaler should buy?
No. Use your own market demand, confirmed supply range and service objectives.
Should every available combination be stocked?
Not necessarily. Evaluate demand, minimum quantities, holding exposure and an alternative supply route.
Should reorder planning use sales only?
Include other reliable demand signals where available, especially requests lost during stockouts, and keep assumptions explicit.
Further reading
These external references provide background context. Product availability and performance claims must still be confirmed for the exact item being purchased.