Know When to Reorder

A Malaysian bookshop wanted to know one thing: is the right stock on the shelf at the right time? Two years of sales said the shop is profitable, but leaking money two ways at once.

The shop sells 385 titles, books, school workbooks and stationery, through walk-in customers, online orders, and bulk orders from schools and tuition centres. The source recorded sales only, so stock-on-hand was reconstructed by simulation calibrated to the shop's actual ordering pattern, with every assumption documented and adjustable.

The analysis covers 101,980 sales lines across the 385 titles, January 2024 to December 2025. The bigger leak is timing. Running out of stock cost about RM1.49 million in sales over the two years, roughly 8% of revenue, and workbooks alone account for RM860,000 of it. These are not titles the shop forgot to stock; they carry plenty most of the year, then empty out at the exam-season peak. Demand is sharply seasonal: January runs 52% above the average month and December 36% above, while June and July fall to about two-thirds of average.

The smaller leak is frozen cash. About RM7,700 sits in 14 dead or overstocked titles, led by UPSR exam books for an exam abolished in 2021, two of them holding more than four years of supply.

Concentration runs through both: 92 titles, under a quarter of the range, make 80% of revenue, and bulk school and tuition orders drive 81% of sales.

The honest takeaway is that the inventory problem is timing, not quantity. The shelves are not too empty or too full on average; they hold the wrong thing at the wrong moment. The fix is a per-title reorder point, safety stock and order size, with extra seasonal cover on the exam and back-to-school workbooks.

Recovering even half the lost sales adds about RM372,000 in revenue and RM149,000 in profit a year, from better timing rather than a bigger budget.