Why stock records are a shipping issue
A parcel can only leave the building if the item exists, is where the system says it is, and is available to be picked. That makes inventory management the first link in the shipping chain. When it is weak, problems show up as cancelled orders, backorders, slow picking, and parcels that contain the wrong item. When it is strong, orders move through packing with few interruptions.
Inventory management covers three practical questions: how many of each item do we have, where is it, and when do we need more? Each one affects what can ship and when.
How many: stock counts you can trust
The number on screen should match the number on the shelf. Differences arise from picking errors, unrecorded returns, damaged goods, theft, miscounted deliveries and items put in the wrong place. Even a small error rate causes pain. Selling an item that is not there leads to an apology, a refund and a customer who may not return.
Several habits keep stock levels dependable:
- Count on receipt. Check inbound deliveries against the paperwork before recording them, and note shortages and damage straight away.
- Update at every movement. Picks, returns, write-offs and transfers should all change the record at the time they happen, not at the end of the week.
- Run cycle counts. Instead of one yearly shutdown to count everything, count a small section regularly, focusing on fast-moving and high-value lines first. Differences found this way point to the process that caused them.
- Separate categories. Keep returned, damaged and quarantined items apart from sellable stock, so they are never picked by mistake.
Scanning can help considerably; the role of barcode scanning at pack stations also applies to stock movements. Larger operations often rely on warehouse management systems to keep counts current as items move.
Where: locations that make picking quick
Knowing that 40 units exist is not enough if a picker must search for them. Assigning each product a defined location, such as an aisle, shelf and bin, and recording it, shortens picking time and reduces mistakes. Good practice includes:
- Labeling shelves clearly and consistently.
- Keeping one product in as few locations as practical, or recording every location if split.
- Placing popular items where they are easiest to reach, as described under warehouse slotting.
- Keeping similar-looking items apart to avoid mix-ups.
For small sellers working from a spare room, a labeled shelf and a simple sheet may be enough. The principle is the same at any size: every item has a home, and the record shows it.
When: reorder points and safety stock
A reorder point is the stock level at which you place a new order, so that replacement stock arrives before you run out. A common way to set it is:
reorder point = (average daily sales x lead time in days) + safety stock
For example, suppose a product sells about 20 units a day, the supplier typically delivers in 5 days, and you hold a safety stock of 40 units to cover variation. Then average demand during the lead time is 20 x 5 = 100 units, and the reorder point is 100 + 40 = 140 units. When stock falls to 140, you reorder. If sales rise to 30 a day, the same formula gives 30 x 5 + 40 = 190, showing why the number needs regular review.
Safety stock is a judgment. Too little risks stock-outs when a delivery runs late; too much ties up cash and space. Higher variability in demand or lead time generally calls for more of it. The figures above are only an illustration, and real lead times and demand should come from your own records.
Effects on shipping performance
Inventory affects shipping in several ways that are easy to overlook:
- Order promise. Showing only what is truly available lets you set realistic delivery dates and delivery expectations.
- Dispatch speed. Items that are easy to find get packed sooner, helping meet cut-off times.
- Split shipments. If part of an order is out of stock, you may have to send two parcels, doubling postage. Good stock planning reduces this.
- Packaging. Knowing which items are held in stock lets you buy the right boxes and filler in advance.
- Returns. Returned goods that are inspected and restocked quickly return to available stock; delays leave sellable items idle.
Dealing with peaks and shortages
Demand is rarely steady. Planning for seasonal demand means building stock ahead of known peaks, while respecting space and cash limits. When supplies are unreliable, as during supply chain disruptions, a wider buffer of key items may be sensible, in contrast to the lean approach of just-in-time shipping. The right balance depends on the product and the cost of running out.
ABC thinking: focus where it matters
Not every item needs equal attention. A widely used approach sorts items into three groups: A items are the few that account for most sales value or volume, B items sit in the middle, and C items are the long tail. Count and review A items most often, keep tighter safety stock on them, and give them the best locations. C items can be checked less often with simpler rules.
Tying it together
Good inventory management is mostly routine discipline: record movements promptly, count regularly, label locations, set sensible reorder points and revisit them. None of it is glamorous, but it removes a long list of shipping problems before they start. Review a few simple measures each month, such as stock accuracy from counts, the number of orders delayed by stock issues, and the number of stock-outs on key lines, and use them to decide where to improve next.