Cost Accounting · Material Costs

Inventory Control Techniques and Stock Levels for CMA Inter

Updated 10 October 2026 · Fact-checked

Stock levels are fixed quantities (reorder, minimum, maximum, danger) that tell the store when to order and when stock is too low or too high. Techniques like ABC, VED and FSN decide where to focus control. To solve numericals, compute each level from usage and lead time using the standard formulas.

Understand Inventory Control Techniques and Stock Levels

Inventory control has two aims: never stop production for want of material, and never lock up more money in stock than needed. Too little stock causes stoppages and rush purchases. Too much stock causes storage cost, obsolescence, theft and blocked funds.

To manage this, the store sets stock levels. The reorder level is the stock at which a purchase order is placed. The minimum level is the safety floor you should not fall below in normal conditions. The maximum level is the ceiling you should not exceed. The danger level is below minimum: at this point, urgent action such as emergency purchase is needed. The average stock level is the midpoint of minimum and maximum.

You cannot control every item equally. ABC analysis ranks items by annual consumption value. A items are few in number but high in value, so they get tight control. C items are many but low in value, so they get simple control. B items sit in between.

VED analysis classifies items by criticality: Vital (production stops without it), Essential (shortage causes loss but can be managed) and Desirable (shortage causes little harm). FSN analysis classifies by movement: Fast-moving, Slow-moving and Non-moving. ABC uses value, VED uses importance, FSN uses usage rate. They can be combined.

Perpetual inventory means continuous record of receipts, issues and balances in bin cards and stores ledger, with continuous stock taking: counting a few items every day through the year, and comparing physical count with records, without stopping the factory.

Key rules to remember

Reorder level (ROL): ROL = Maximum consumption × Maximum reorder period; Reorder period is the lead time. Use maximum usage and maximum lead time.
Minimum level: Minimum level = ROL − (Normal consumption × Normal reorder period); Normal consumption is the normal (average) usage given in the question; the normal reorder period is the normal lead time.
Maximum level: Maximum level = ROL + ROQ − (Minimum consumption × Minimum reorder period); ROQ is the reorder quantity, often the EOQ.
Danger level: Danger level = Average consumption × Lead time for emergency purchases; Some questions use minimum level × emergency lead time ratio; follow the data given.
Average stock level: Average stock level = (Minimum level + Maximum level) ÷ 2; Alternative: Minimum level + ½ × ROQ. Both are accepted; use the one the question suits.
ABC value: Annual consumption value = Annual quantity × Unit price; Rank in descending order of value, then compute cumulative % of items and of value.
Inventory turnover ratio: Turnover = Cost of material consumed ÷ Average stock; Used to spot slow-moving items.

How to solve Inventory Control Techniques and Stock Levels questions

Use this order for any stock level or classification question.

1List the data given: normal, maximum and minimum usage, normal, maximum and minimum lead time, ROQ, and emergency lead time.
2Check units: keep usage per week or per day consistent with lead time in the same unit.
3Compute reorder level first, as other levels depend on it.
4Compute minimum level, then maximum level, then danger and average levels as asked.
5For ABC, calculate value of each item, sort in descending order, and compute cumulative value %.
6Assign classes using the cut-offs given, or the usual pattern where few items carry most of the value.
7Write a short remark on the control action for each class or level.
8For perpetual inventory theory, state the records used, the counting method and the benefit.

Quickest way: Stock levels in four lines

When to use it: Use when a numerical asks for several levels at once and time is short.

Write ROL = max usage × max lead time and calculate.
Write minimum = ROL − normal usage × normal lead time.
Write maximum = ROL + ROQ − min usage × min lead time.
Write average = (min + max) ÷ 2 and danger = usage × emergency lead time.

Common mistakes in Inventory Control Techniques and Stock Levels

Using normal usage and lead time to compute reorder level.
Students mix up the formulas for ROL and minimum level.
Fix: ROL uses the maximum of both. Minimum level uses the normal values.
Forgetting to subtract minimum consumption during minimum lead time in maximum level.
Students remember ROL + ROQ and stop.
Fix: Always write the full formula: ROL + ROQ − (min usage × min lead time).
Mismatched units, such as monthly usage with weekly lead time.
Data are given in different time units.
Fix: Convert everything to one unit before any multiplication.
Sorting ABC items by quantity or unit price instead of total value.
The price column looks like the key figure.
Fix: Multiply quantity by price, then sort by that annual value.
Treating ABC and VED as the same.
Both split items into classes by importance.
Fix: ABC is based on money value of consumption. VED is based on how critical the item is to production.
Describing perpetual inventory as a single year-end count.
Confusing it with periodic stock taking.
Fix: Perpetual inventory is the continuous recording of balances, and continuous stock taking verifies them through the year.

Worked examples

Example 1

A company uses a material with: normal usage 100 units per week, maximum usage 150 units per week, minimum usage 50 units per week. Lead time: normal 4 weeks, maximum 6 weeks, minimum 2 weeks. ROQ is 600 units. Calculate reorder level, minimum level, maximum level and average stock level.

Show the solution

Reorder level = 150 × 6 = 900 units.
Minimum level = 900 − (100 × 4) = 900 − 400 = 500 units.
Maximum level = 900 + 600 − (50 × 2) = 1,500 − 100 = 1,400 units.
Average stock level = (500 + 1,400) ÷ 2 = 950 units.

Answer: Reorder level 900 units; minimum level 500 units; maximum level 1,400 units; average stock level 950 units.

Example 2

Five items have annual consumption: P: 2,000 units at ₹50; Q: 500 units at ₹20; R: 100 units at ₹400; S: 4,000 units at ₹5; T: 200 units at ₹10. Classify them under ABC analysis, taking A as the items needed to make up about 70% or more of cumulative value (up to about 80% to 85%), B as the next items taking cumulative value to about 95%, and C as the rest.

Show the solution

Values: P = 2,000 × 50 = 1,00,000; Q = 500 × 20 = 10,000; R = 100 × 400 = 40,000; S = 4,000 × 5 = 20,000; T = 200 × 10 = 2,000.
Total value = 1,00,000 + 10,000 + 40,000 + 20,000 + 2,000 = 1,72,000.
Sort descending: P 1,00,000; R 40,000; S 20,000; Q 10,000; T 2,000.
Cumulative value %: P = 58.14%; R = 81.40%; S = 93.02%; Q = 98.84%; T = 100%.
P alone is 58.14%, below the 70% mark, so R is also needed to cross it. P and R together reach 81.40%, so both are A.
S takes cumulative value to 93.02%, within the B band that ends at about 95%, so S is B.
Q and T are the remaining low-value items (together 6.98% of value), so they are C.

Answer: A: P and R (81.40% of value together; P 58.14% and R 23.26%). B: S (11.63% of value). C: Q and T (6.98% of value together). Tight control for P and R, moderate control for S, simple control for Q and T.

Exam tips

Write each level formula before substituting numbers; step marks go to the formula and the working.
In ABC numericals, show the value column and cumulative percentage column clearly in a small table-style list.
For theory questions, give a one-line difference between ABC, VED and FSN and the basis of each.
Mention that perpetual inventory with continuous stock taking avoids stopping production for a full count and finds discrepancies early.
In MCQs, check which level the question names: reorder, minimum, maximum or danger, since options often contain the other levels' values.

Practice questions from Material Costs

Inventory Control Techniques and Stock Levels in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

CA IntermediateInventory Control and Stock Levels

Inventory Control Techniques and Stock Levels: frequently asked questions

What is the difference between ABC and VED analysis?

ABC analysis classifies items by the money value of annual consumption. VED classifies items by how critical they are to production. An item can be C in ABC but Vital in VED, such as a cheap but essential part.

How do you calculate the danger level?

Danger level is commonly taken as average consumption multiplied by the lead time needed for emergency purchases. Some questions give a different basis, so use the data in the question.

What is the average stock level?

It is the midpoint of the minimum and maximum levels. You can also compute it as minimum level plus half of the reorder quantity.

What is the difference between perpetual inventory and continuous stock taking?

Perpetual inventory is the system of continuously recording receipts, issues and balances. Continuous stock taking is the physical verification of selected items through the year to check those records.