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ACCA Applied Skills · Financial Management

Management of inventories, accounts receivable, accounts payable and cash: formula sheet

Full chapter guide

Key formulas

Inventory days
Inventory days = (Inventory ÷ Cost of sales) × 365
For a manufacturer you may split into raw materials (÷ purchases or material usage), WIP (÷ cost of production) and finished goods (÷ cost of sales).
Receivable days
Receivable days = (Trade receivables ÷ Credit sales) × 365
Use credit sales, not total sales, if the data gives both. Use revenue only if no split is given.
Payable days
Payable days = (Trade payables ÷ Credit purchases) × 365
Use credit purchases if given. Otherwise use cost of sales as an approximation and state the assumption.
Cash operating cycle
Cycle = Inventory days + Receivable days − Payable days
For a manufacturer, add raw material, WIP and finished goods days, then add receivable days and subtract payable days.
Working capital
Working capital = Current assets − Current liabilities
An amount at a point in time, not a period.
Current ratio and quick ratio
Current ratio = Current assets ÷ Current liabilities; Quick ratio = (Current assets − Inventory) ÷ Current liabilities
Rules of thumb such as 2:1 and 1:1 vary by industry. Do not treat them as fixed targets.
Total working capital
Net working capital = Current assets − Current liabilities
Used to compare the level of investment under different policies.
Split of current assets
Total current assets = Permanent current assets + Fluctuating current assets
Permanent is the minimum level needed all year; fluctuating is the seasonal or cyclical extra.
Matching policy
Long-term finance = Non-current assets + Permanent current assets; Short-term finance = Fluctuating current assets
A benchmark. Aggressive uses more short-term finance than this; conservative uses more long-term finance.
Current ratio
Current ratio = Current assets ÷ Current liabilities
A higher ratio normally suggests a more conservative position.
Cost of a financing mix
Annual finance cost = Σ (amount of funds × interest rate)
Use this to compare policies in numerical questions. Cost of each source depends on the rates given.
Economic order quantity
EOQ = √(2 × Co × D ÷ Ch)
Co = cost per order, D = annual demand in units, Ch = holding cost per unit per year. D and Ch must use the same time period (annual).
Total annual ordering and holding cost
Total cost = (D ÷ Q) × Co + (Q ÷ 2) × Ch
Q is the order size. Average stock is Q ÷ 2 because stock falls steadily from Q to zero.
Total annual cost including purchases
Total cost = D × P + (D ÷ Q) × Co + (Q ÷ 2) × Ch
P is the price per unit at that order size. Use this form for bulk discount decisions.
EOQ cost balance
At EOQ: (D ÷ Q) × Co = (Q ÷ 2) × Ch
A quick check on your answer. If the two costs differ at EOQ, something is wrong.
Reorder level (no buffer)
Reorder level = usage per period × lead time
With uncertain demand or lead time, many questions use maximum usage × maximum lead time.
Reorder level with buffer stock
Reorder level = average usage × average lead time + buffer stock
Use whichever approach the question's data points to.
Receivable days
Receivable days = (Trade receivables ÷ Credit sales) × 365
Use credit sales if given, otherwise revenue. Use the days in the year the question uses (365 unless told otherwise).
Average receivables from days
Receivables = Annual credit sales × days ÷ 365
Used to find the change in receivables when a policy changes. Work out each customer group separately.
Financing cost or saving of receivables
Finance cost = Receivables × interest rate
Use the rate at which the company borrows (or earns if cash is surplus). A fall in receivables saves interest.
Annual cost of early settlement discount (compound)
Annual cost = [100 ÷ (100 − d)]^(365 ÷ t) − 1, where d = discount % and t = days of credit given up
t = normal credit period − discount period. Compare with the company's cost of short-term finance.
Approximate (simple) annual cost of discount
Approx. cost = [d ÷ (100 − d)] × (365 ÷ t)
Quicker but lower than the compound figure. Use compound unless the question says otherwise.
Cost of discount in money
Discount cost = Discount % × sales paid early
Only sales that take the discount count.
Factoring net benefit
Net benefit = admin savings + bad debt savings + finance saving − factor fees − extra finance charges
Finance saving comes from lower receivables and from replacing overdraft with cheaper or dearer factor finance.
Simple cost of forgoing the discount (per period)
d ÷ (100 − d)
d is the discount % . For 2% this is 2 ÷ 98 = 2.04%. This is the cost over the extra credit period, not a year.
Annualised cost (compound)
(1 + d ÷ (100 − d))^(365 ÷ N) − 1
N is the days of extra credit gained by not taking the discount (final due date minus discount date). This is the preferred and more accurate method.
Annualised cost (simple)
d ÷ (100 − d) × 365 ÷ N
Quick approximation. It gives a lower figure than the compound method and understates the true cost. Use compound unless the question asks for simple.
Payables days
Trade payables ÷ Cost of sales (or credit purchases) × 365
Use purchases if given. Use year-end payables unless an average is requested.
Decision rule
Take the discount if annualised cost of forgoing it > cost of short-term finance
If the cost of finance is higher, it is cheaper to forgo the discount and pay later.
Baumol optimal sale size
Q = √(2 × C × S ÷ i)
C = cost per transaction, S = total cash needed for the period, i = interest rate for the same period (the opportunity cost of holding cash). Q is the amount of securities to sell each time.
Baumol total cost
Total cost = (Q ÷ 2) × i + (S ÷ Q) × C
Holding cost on the average balance (Q ÷ 2) plus transaction costs. At the optimum Q the two parts are equal, which is a quick check.
Number of transactions
Transactions = S ÷ Q
Use it to find the transaction cost part of the total cost.
Miller-Orr spread
Spread = 3 × (¾ × transaction cost × variance of daily cash flows ÷ daily interest rate)^(1/3)
Use a daily interest rate when the variance is of daily flows. Variance = (standard deviation)². The cube root is the 1/3 power.
Miller-Orr upper limit
Upper limit = lower limit + spread
The lower limit is set by management, for example a safety buffer or overdraft facility. It is a given in the question.
Miller-Orr return point
Return point = lower limit + (spread ÷ 3)
At the upper limit, buy securities to bring cash back to the return point. At the lower limit, sell securities to return to it.
Annual rate to daily rate
Daily rate = annual rate ÷ 365 (simple), or (1 + annual rate)^(1/365) − 1 (compound)
Follow the question's instruction. If none is given, state the method you use.
Simple interest for part of a year
Interest = Amount × annual rate × (months ÷ 12)
Use for deposits, overdrafts and loans of less than a year. Use days ÷ 365 if days are given.
Treasury bill yield (discount instrument)
Return over the period = (Face value − Price paid) ÷ Price paid
Divide by the price paid, not the face value. Annualise by scaling with 12 ÷ months, or compound if the question asks for the effective rate.
Effective annual rate (EAR)
EAR = (1 + r)^n − 1, where r is the return per period and n is the number of periods in a year
Use it to compare instruments with different terms or compounding.
Net benefit of investing
Net gain = Interest earned − Costs (fees, lost interest or higher borrowing cost)
Compare with the alternative of simply holding cash or repaying an overdraft.
Risk, return and liquidity rule
Higher return ⇒ usually lower liquidity and/or higher risk
A general tendency, not a law. Use it to justify a choice in written answers.

Quick revision

  • Cash operating cycle = inventory days + receivable days − payable days.
  • Inventory days use average or closing inventory ÷ cost of sales × 365; receivable days use receivables ÷ credit sales × 365; payable days use payables ÷ credit purchases (or cost of sales) × 365.
  • EOQ = √(2 × Co × D ÷ Ch); at the EOQ, annual ordering cost equals annual holding cost.
  • With a bulk discount, compare total annual cost (purchase + ordering + holding) at the EOQ and at each discount quantity.
  • A conservative policy holds high working capital and uses long-term finance; an aggressive policy holds low working capital and uses more short-term finance.
  • Annual cost of forgoing a discount = (1 + d ÷ (100 − d))^(365 ÷ n) − 1; take the discount if this is higher than your cost of borrowing.
  • Factoring can speed up cash and cut admin costs, but it costs fees and interest and may affect customer relationships.
  • Reducing receivable days frees up cash; the saving is the reduction in receivables × the cost of finance.
  • Cash forecasts show timing only: leave out non-cash items such as depreciation.
  • Overtrading means growth without enough finance, so look for a rising need for cash and a strained overdraft.
  • Surplus cash should be placed with attention to liquidity, risk and return; shortfalls can be met by overdrafts, loans or tighter working capital.
  • In a Section C answer, state the calculation, then give a recommendation and one or two risks.

Common mistakes

  • Adding payable days instead of subtracting them. Fix: Remember payables are cash you have not paid yet. They shorten the cycle, so subtract.
  • Using revenue for inventory days and payable days. Fix: Use cost of sales (or purchases) for inventory and payables. Revenue is for receivables only.
  • Mixing up investment policy and financing policy. Fix: Ask first: is this about how much is held, or how it is paid for? Answer only that part, and treat the other separately.
  • Saying conservative financing means less long-term finance. Fix: Conservative financing means more long-term finance, which is safer but costlier. Aggressive means more short-term finance.
  • Using Q instead of Q ÷ 2 for holding cost. Fix: Always write (Q ÷ 2) × Ch. Then check that ordering cost equals holding cost at EOQ.
  • Mixing time periods, such as monthly demand with annual holding cost. Fix: Convert everything to annual figures before using the formula, and say so in your working.
  • Calculating the discount cost as d ÷ 100 without annualising. Fix: Divide by (100 − d), then scale by 365 ÷ t. Always compare annual with annual.
  • Using the wrong number of days saved, for example using the full credit period instead of the credit period minus the discount period. Fix: Write t = normal days − discount days before you start. For 2/10 net 30, t = 20.
  • Using d ÷ 100 instead of d ÷ (100 − d). Fix: The discount is based on the invoice price. You actually pay 100 − d if you pay early, so the cost is measured on that smaller amount.
  • Using the full credit period as N. Fix: N is only the extra time gained by not taking the discount. For 2/10 net 30, N is 20 days, not 30.

Exam tips

  • In objective tests, read which figure each ratio needs. Wrong denominators are the usual trap.
  • Use 365 days unless told otherwise and keep decimals until the final answer.
  • In written answers, give the calculation first, then comment on causes, effects and actions. Calculation alone scores little on the discussion marks.
  • For overtrading, link each symptom to the data given, and give remedies as well as symptoms.
  • Remember that industry context matters. Say whether a change is good or bad for that type of business.
  • Always define permanent and fluctuating current assets before classifying a policy. It earns marks in written answers and helps you in objective tests.
  • In objective questions, work out the matching level of long-term finance first. Then compare it with the actual figure.
  • In Section C, give both sides: return and cost against risk and flexibility. Then apply it to the scenario, such as seasonal sales.