ABC and XYZ together: the nine-cell matrix

ABC analysis rates an item's value and XYZ analysis rates how stable its demand is. Using them separately is useful, but together they give a practical answer for each item: how much stock to hold, how often to count and how to place orders. The result is the nine-cell matrix: value on three levels (A, B, C) and stability on three levels (X, Y, Z).

The nine cells and their policies

• AX — valuable and stable. Automatic reordering, a small safety stock, frequent small batches. The easiest and most rewarding cell.
• AY — valuable, demand fluctuates. A moderate safety stock and a weekly review of the forecast.
• AZ — valuable, demand swings sharply. The hardest cell. A quick arrangement with the supplier, daily monitoring and a search for the cause of demand spikes: a promotion or a large customer?
• BX and BY — a standard reorder point and moderate stock.
• BZ — limit stock and work to order where possible.
• CX — a simple rule, large batches, infrequent counting. The value is low, so the cost of holding it is small too.
• CY — minimal stock and simplified control.
• CZ — delist or sell to order only. The main place where cash gets stuck.

An example: a shop with 300 positions

Suppose both analyses are done and the positions fall into cells as follows: AX 25, AY 20, AZ 8, BX 30, BY 45, BZ 25, CX 40, CY 55, CZ 52. That makes 300 in total.

Group A has 53 positions (about 18 percent), yet they produce most of the sales. Of these only 8, the AZ cell, about 3 percent of all positions, take the most analyst time. Together with AY, 28 positions get a weekly review, which is manageable work for one person.

In the bottom right corner sits the CZ cell: 52 positions, or 17 percent of the range. They bring little income and their demand is irregular. Decide on each: stop selling it, clear the remaining stock at a discount or switch it to order-only. The cash released here can go into stock for the items in the AX cell.

The matrix also simplifies the counting plan. Count group A once a month (53 positions), group B once a quarter (about 33 a month) and group C twice a year (about 25 a month), and you get roughly 110 positions a month, an average of 5 per working day. That is no burden for one storekeeper, and there is no need to close the warehouse and count everything in a single day.

Reduce nine cells to three practical groups

Nine separate rules are hard to remember, so merge the cells into three groups:

1. Automate: AX, BX, CX. Demand is stable and the decision follows a simple rule.
2. Manage closely: AY, AZ, BY. Value or fluctuation is high, and analyst time goes here.
3. Cut back or switch to order-only: BZ, CY, CZ. Limit stock and release cash.

Building it in Excel

1. Calculate the ABC and XYZ groups separately and give each item two letters.
2. Join the letters: the formula A2 & B2 produces a code like "AX".
3. Create a pivot table: ABC in rows, XYZ in columns, and the number of positions and sales value as the values.
4. Next to each cell write the policy briefly: who acts, when and by what rule.

Common mistakes

• Building the matrix once. Items move between cells, so refresh it every quarter.
• Working with a dirty catalogue. If one item is entered as two records, its sales are split and it lands in the wrong cell.
• Solving AZ only with a large stock. A large stock of an expensive item means a lot of frozen cash; first find out why demand is unstable.
• Removing CZ items without checking. Some of them are bought together with other goods, so check joint sales.
• Trying to write detailed instructions for each of the nine cells. Three groups are enough.

Conclusion

The matrix turns a complex analysis into three or four decisions: what to automate, what to watch, what to cut. For it to work, sales data and balances must be reliable. CountLab builds the ABC/XYZ matrix together with stock-count results and helps prepare a cycle count plan and a management report.