Stock problems are usually process problems. Businesses lose sales when popular items run out, lose money when goods expire or disappear, and lose time when the recorded quantity cannot be trusted.
Create one record for each item with a clear name, category, buying cost, selling price, supplier, and current quantity. Set a reorder point based on normal sales and supplier lead time. Count high-value or fast-moving items more often than slow-moving items. Record damaged, expired, returned, and personal-use stock separately instead of silently changing the number.
Make every sale and stock-in movement part of the same routine. Restrict editing access where possible and investigate large differences without blaming staff first. Review a short stock report weekly: top sellers, items below reorder level, dead stock, and margin. A simple consistent process will produce better decisions than a complicated system nobody updates.