What it means
Most businesses hold far more items than they can watch closely. ABC analysis ranks them by their annual consumption value, which is how much money flows through each item over a year, and splits the ranked list into groups.
The A group is typically a small share of items, often around 10% to 20%, that make up roughly 70% to 80% of total value. The B group is a middle band, and the C group is the long tail of low-value items that together make up only a small share of the money.
The groups then receive different treatment. A items get tight control, frequent counts, accurate forecasts and close supplier relationships, while C items get simple rules, larger order quantities and fewer checks.
This saves management time and often reduces the cash tied up in stock. The method is an application of the Pareto principle, which says that a minority of causes produce a majority of effects.
It is not an exact law, so the percentages vary from business to business. Finance teams use it beyond warehouses.
It can rank customers by revenue, suppliers by spend or products by profit, and it helps to decide where audit effort, credit control or negotiation time will have the biggest payoff. One limitation is that value is not the same as criticality.
A cheap part that stops a production line when it runs out may belong in a high-attention group, so many firms combine the analysis with a rating of how damaging a shortage would be.
In practice
Real-world examples
Example 1
A hardware distributor ranks 3,000 products by annual sales value. About 250 products produce 75% of revenue, and these are counted weekly and never allowed to run out. The slow-moving tail is ordered in bulk twice a year.
Example 2
A hospital pharmacy applies the method to its medicines. High-value drugs are tightly controlled, and a few cheaper but life-critical drugs are added to the top group regardless of cost. Routine supplies are reordered automatically when stock drops below a set level.
Example 3
A software company ranks its customers by annual revenue. A small group of accounts generates most of the income, so the finance director assigns them senior account managers and monitors their payment behaviour closely. Smaller customers are served through standard processes.
Think of it
Think of managing your personal wardrobe like an ABC Analysis. Your expensive suit or winter coat gets prime closet space and careful dry cleaning, while your socks and basic t-shirts live in a simple drawer and are bought in bulk.
Formula
Calculation
Annual consumption value = Annual usage in units x Cost per unit
Share of total = Item value / Total value of all items
Suppose a business has five items. Item P: 1,000 x $50 = $50,000. Item Q: 500 x $40 = $20,000. Item T: 6,000 x $2 = $12,000. Item R: 2,000 x $5 = $10,000. Item S: 4,000 x $2 = $8,000. Total value = 50,000 + 20,000 + 12,000 + 10,000 + 8,000 = $100,000. P is 50% and Q is 20%, so together they form 70% of value and become class A. T and R add 22%, taking the cumulative share to 92%, and form class B, while S at 8% is class C.Case study
Seen in the real world
Calder and Finch is an illustrative, fictional furniture maker that stocks 2,400 components and had been counting all of them every quarter. The count took five staff three days, and stock-outs still occurred on the parts that mattered most.
The operations manager ran an ABC analysis and found that 240 components represented about 78% of the annual spend. She moved those into a weekly count and a tighter reorder process, and she reduced the count for the C items to once a year.
Within a year stock-outs on key components fell by more than half, and inventory counting time dropped by about a third. The illustrative lesson is that treating every item equally wastes effort on the items that matter least.
Watch out
Common mistakes
- Ranking items by unit price rather than by annual usage multiplied by price, which gives a misleading picture of where the money goes.
- Treating the 70%, 20% and 10% cut-offs as fixed rules, when each business sets the boundaries that suit its own data.
- Ignoring criticality, which can leave a cheap but essential part in the lowest-attention group.
Questions
People also ask
What do A, B and C stand for?
They are simply labels for three groups ranked by value, with A the most valuable group, B the middle and C the least valuable.
How often should the analysis be repeated?
At least once a year, and more often if demand, prices or the product range change, because items can move between groups.
Is ABC analysis only for inventory?
No, it can be applied to customers, suppliers, products or expenses, wherever a few items account for most of the value.