A to Z Costing Knowledge Glossary — Letter O
Investopedia-style costing concepts explained with formulas, practical examples, comparisons, and exam-focused teaching tips.
1 Overheads
| Category | Cost Element |
|---|---|
| Best Used In | Cost accumulation, pricing, variance analysis |
| Key Formula | Indirect Material + Indirect Labour + Indirect Expenses |
| Exam Importance | Extremely High |
Overheads represent the aggregate of all indirect costs incurred by an organization. They are the expenses that keep the business running but cannot be conveniently or economically traced directly to a specific unit of production or job.
Because you cannot say exactly how much factory rent belongs to one specific chair, overheads must be collected in “cost pools” and then mathematically spread (absorbed) across all products produced during the period.
- Calculating the Total Cost of a product
- Valuing closing inventory for financial statements
- Setting departmental budgets
A bakery buys flour (Direct Material) to bake a cake. However, the oven electricity, the baker’s apron, the store rent, and the cashier’s salary are all Overheads. The bakery must figure out a way to charge a tiny fraction of the rent and electricity into the price of every cake sold to stay profitable.
Direct Costs: Wood (₹500), Carpenter Wages (₹300) = Prime Cost (₹800).
Overheads: Glue (₹10 – Indirect Material) + Supervisor Salary (₹50 – Indirect Labour) + Factory Rent (₹40 – Indirect Expense) = ₹100.
Total Factory Cost = ₹800 + ₹100 = ₹900.
- Identify all costs incurred in the business.
- Strip out anything that can be directly traced to a single unit (Direct Costs).
- Classify the remaining indirect costs by function: Production, Administration, or Selling & Distribution.
- Allocate or apportion these functional pools to cost centres.
| Overheads vs. Prime Cost | Prime Cost is the sum of all *Direct* costs. Overheads are the sum of all *Indirect* costs. Prime Cost + Factory Overheads = Factory/Works Cost. |
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2 Overhead Absorption (Recovery)
| Category | Cost Allocation |
|---|---|
| Best Used In | Full/Absorption Costing, Pricing |
| Key Formula | Actual Base Units × Pre-determined Absorption Rate |
| Exam Importance | Very High |
Overhead Absorption (or Recovery) is the final step in overhead accounting. It is the process of charging the total overhead costs accumulated in a production department directly into the cost of the individual products passing through that department.
First, overheads are gathered (Allocation) and shared among departments (Apportionment). Finally, the department takes its share and “absorbs” it into the products using a logical base—like labour hours, machine hours, or a percentage of prime cost.
- Determining fully-loaded product costs for pricing
- Ind AS 2 compliant inventory valuation
- Job-order quoting in service and manufacturing industries
A printing department incurs ₹1,00,000 in monthly overheads. They estimate the printing press will run for 1,000 hours this month. The absorption rate is ₹100/hour. If a customer orders 500 wedding invitations that take 2 hours to print, the accountant “absorbs” ₹200 of the department’s overhead into the customer’s final bill.
Pre-determined Overhead Absorption Rate (OAR) = ₹50 per Direct Labour Hour.
Job No. 101 required ₹2,000 of materials and 10 Direct Labour Hours.
Overhead Absorbed into Job 101 = 10 hours × ₹50 = ₹500.
Total Cost of Job 101 = ₹2,000 (Mat) + Wages + ₹500 (Absorbed OH).
- Calculate a pre-determined rate at the start of the year based on budgets.
- Track the actual number of hours/units each job consumes during the year.
- Multiply the actual activity by the standard rate to charge the job.
- Compare Total Absorbed OH against Total Actual OH at year-end to find over/under absorption.
| Absorption vs. Apportionment | Apportionment shares a common cost (rent) between departments. Absorption takes that departmental cost and pushes it into the product. |
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3 Overhead Apportionment
| Category | Cost Allocation |
|---|---|
| Best Used In | Departmental cost analysis, preparing distribution summaries |
| Key Formula | Shared Cost × (Department Base ÷ Total Base) |
| Exam Importance | Very High |
Overhead Apportionment is the process of splitting and distributing common, shared overhead costs among two or more cost centres (departments) on a logical and equitable basis.
When a cost cannot be directly traced to a single department (like the salary of a factory manager who oversees three departments), the cost must be mathematically divided. This ensures no single department unfairly bears the burden of a shared resource.
- Primary Distribution of Overheads (Rent, Electricity)
- Evaluating the true profitability of specific production departments
- Establishing accurate departmental absorption rates
A company pays ₹5,00,000 for factory building insurance. The building houses the Cutting, Assembly, and Finishing departments. The accountant apportions the insurance cost based on the floor area occupied by each department. Assembly occupies 50% of the space, so it is apportioned ₹2,50,000 of the insurance cost.
Factory Rent / Rates / Taxes: Apportioned based on Floor Area.
Depreciation / Insurance of Machinery: Apportioned based on Capital Value of Machines.
Canteen / Welfare Expenses: Apportioned based on Number of Employees.
Electricity (Power): Apportioned based on Machine Horsepower × Hours worked.
- Identify the common overhead expense (e.g., Factory Rent).
- Select the most logical “Benefit Received” base (e.g., Floor area in Sq. Ft).
- Calculate the ratio of the base for each department.
- Distribute the total cost using the calculated ratios.
| Apportionment vs. Allocation | Allocation means the cost belongs 100% to one department (no math needed). Apportionment means the cost is shared, requiring a mathematical split. |
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4 Overhead Absorption Rate (OAR)
| Category | Cost Allocation |
|---|---|
| Best Used In | Job costing, preparing estimates |
| Key Formula | Budgeted Overheads ÷ Budgeted Activity Base |
| Exam Importance | Very High |
The Overhead Absorption Rate (OAR) is a pre-calculated rate used to attach overhead costs to products or jobs. It is always calculated in advance (predetermined) using budgeted figures, rather than waiting for actual year-end data.
If a business waits until December 31st to find out exactly what its electricity and rent were, it cannot price its products in January. The OAR solves this by using estimates, allowing accountants to cost and price products in real-time as they roll off the assembly line.
- Real-time pricing of customer orders
- Standard costing system implementation
- Calculating Under/Over absorption at period-end
A garage estimates it will spend ₹12 Lakhs on overheads this year, and mechanics will work 12,000 hours. The OAR is ₹100/hour. If you bring your car in for a 3-hour repair, the garage charges you for parts, mechanic wages, PLUS ₹300 (3 hrs × ₹100) to cover their rent and utilities.
Budgeted Factory Overheads = ₹5,00,000.
Budgeted Machine Hours = 50,000 hours.
Pre-determined OAR = 5,00,000 ÷ 50,000 = ₹10 per Machine Hour.
If Actual Machine hours worked end up being 48,000, the total overhead absorbed will be ₹4,80,000.
- Estimate total overheads for the upcoming year.
- Choose the best base (Direct Labour Hours, Machine Hours, Units, or % of Prime Cost).
- Estimate the total volume of that base for the year.
- Divide to get the OAR.
- Apply this rate to actual production continuously throughout the year.
| Predetermined OAR vs. Actual OAR | Actual OAR is calculated at year-end using actual costs and actual hours. It is rarely used because it is useless for real-time pricing and delays accounting. |
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5 Over-Absorption of Overheads
| Category | Cost Accounting Adjustments |
|---|---|
| Best Used In | Year-end reconciliation, adjusting COGS |
| Key Formula | Absorbed Overheads − Actual Overheads (When Positive) |
| Exam Importance | High |
Over-Absorption occurs when the amount of overhead charged (absorbed) to production using a predetermined rate is greater than the actual overhead costs incurred by the business at the end of the period.
Because the predetermined rate was an estimate, it is rarely perfect. Over-absorption means the business charged “too much” overhead to its products. This usually happens because actual expenses were lower than expected, or because the factory worked far more hours/units than budgeted, soaking up excess cost.
- Reconciling Cost Accounts with Financial Accounts
- Adjusting Cost of Goods Sold (COGS)
- Analyzing capacity utilization efficiency
A factory sets an OAR of ₹50/hour based on a budget of 1,000 hours. The factory actually works 1,200 hours, “absorbing” ₹60,000 into product costs. At year-end, the actual electricity and rent bills arrive, totaling only ₹55,000. The factory has over-absorbed by ₹5,000. They must credit this ₹5k to the P&L to correct the overcharge.
Predetermined Rate = ₹20 per unit. Actual Output = 10,000 units.
Overheads Absorbed = 10,000 × ₹20 = ₹2,00,000.
Actual Overheads Incurred = ₹1,85,000.
Over-Absorption = ₹2,00,000 – ₹1,85,000 = ₹15,000.
- Calculate total overhead absorbed during the year.
- Calculate total actual overhead incurred.
- If Absorbed > Actual = Over-Absorption.
- Treatment: Depending on materiality, carry it forward, write it off to Costing P&L (increasing profit), or use a supplementary rate to adjust WIP, FG, and COGS.
| Over-Absorption vs. Under-Absorption | Under-absorption (Absorbed < Actual) means you didn't charge enough, resulting in a loss that must be debited to P&L. Over-absorption means you charged too much, creating a "gain" that is credited to P&L. |
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6 Opportunity Cost
| Category | Decision Making / Relevant Costing |
|---|---|
| Best Used In | Make or Buy, Acceptance of Special Orders |
| Key Formula | Value of the next best alternative forgone |
| Exam Importance | Extremely High |
Opportunity Cost is the economic benefit, profit, or value that is sacrificed or lost when a company chooses one alternative course of action over another.
It is not an “out-of-pocket” cost (no cash leaves the bank), so it is never recorded in financial accounting. However, in management accounting, failing to include opportunity costs in a decision model guarantees you will make a mathematically flawed, sub-optimal choice.
- Accepting a special order at full capacity (displacing regular sales)
- Deciding whether to use a warehouse for storage or rent it out
- Capital budgeting (investing in Project A means rejecting Project B)
A farmer owns land. He can grow wheat to make ₹1 Lakh, or grow corn to make ₹1.2 Lakhs. If he chooses corn, the opportunity cost of that decision is the ₹1 Lakh he sacrificed by not growing wheat. The true economic profit of the corn is only ₹20,000.
Factory is running at 100% capacity making Product X (Contribution = ₹50/unit).
Management wants to make Component Y internally, which requires displacing the production of 1 unit of Product X.
Cost to Make Component Y: Direct Material (₹20) + Direct Labour (₹30) + Opportunity Cost (₹50 lost contribution from X).
True Relevant Cost to Make Y = ₹100. If an outside supplier offers Y for ₹90, you should BUY it.
- Identify the resource being used (time, machine hours, floor space).
- Ask: “If I didn’t take this action, what is the next most profitable thing I could do with this resource?”
- Calculate the contribution margin of that rejected alternative.
- Add that lost contribution as a “cost” to the new project being evaluated.
| Opportunity Cost vs. Sunk Cost | Sunk costs are past cash outflows that cannot be changed (Irrelevant). Opportunity costs are future cash inflows that are rejected (Highly Relevant). |
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7 Operating Costing (Service Costing)
| Category | Costing Methods |
|---|---|
| Best Used In | Service industries (Transport, Hospitals, Hotels) |
| Key Formula | Total Operating Cost ÷ Total Composite Units (e.g., Passenger-km) |
| Exam Importance | Very High |
Operating Costing (also widely known as Service Costing) is the method used to ascertain the cost of providing a standardized service, rather than manufacturing a physical, tangible product.
Because services are intangible, you cannot calculate the “cost per kilogram.” Instead, costs are grouped into Standing (Fixed) and Running (Variable) charges, and divided by a unique “composite” cost unit, such as a passenger-kilometer, a room-night, or a patient-day.
- Transport Companies (Buses, Airlines, Trucking)
- Hospitals and Healthcare facilities
- Hotels, Cinemas, and Boiler/Power houses
A bus company needs to set ticket prices. They aggregate the fixed costs (insurance, road tax, driver salary) and variable costs (diesel, tires). They calculate that the bus carried 50 passengers over 10,000 kilometers this month (500,000 Passenger-Kms). By dividing total costs by 500,000, they find the cost to transport one person for one kilometer, forming the basis for ticket pricing.
Total Monthly Cost of running a truck = ₹1,50,000.
The truck carries 10 Tons of goods for a distance of 3,000 Kms in the month.
Composite Unit (Tonne-Kms): 10 Tons × 3,000 Kms = 30,000 Tonne-Kms.
Cost per Tonne-Km: ₹1,50,000 ÷ 30,000 = ₹5.00.
- Determine the specific Composite Unit for the industry (e.g., Patient-Days for a hospital).
- Calculate total Absolute/Commercial units (Number of buses × Capacity × Distance × Days × Occupancy %).
- Segregate costs into Fixed (Insurance, Garage rent) and Variable (Fuel, Spares). Note: Driver wages can be either depending on terms.
- Divide total cost by total composite units.
| Absolute Tonne-Km vs. Commercial Tonne-Km | Absolute calculates distance for each trip individually. Commercial averages the load over the total distance. Examiners test this specific calculation heavily in Transport Costing. |
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8 Ordering Cost
| Category | Inventory Management |
|---|---|
| Best Used In | Calculating Economic Order Quantity (EOQ) |
| Key Formula | (Annual Demand ÷ Order Size) × Cost per Order |
| Exam Importance | High |
Ordering Cost represents all the variable administrative, logistical, and clerical expenses incurred every single time a company places a purchase order with a supplier.
It includes the cost of raising the requisition, processing the invoice, inspecting the goods upon arrival, and transportation. In inventory management, Ordering Cost is locked in a tug-of-war with Holding Cost: ordering in bulk reduces the number of orders (lowering ordering costs) but skyrockets the cost of holding the inventory.
- Input parameter for the EOQ formula
- Evaluating Just-In-Time (JIT) viability
- Supply chain optimization
A restaurant needs 1,200 bottles of wine a year. If they order 100 bottles a month (12 orders), and it costs ₹500 in admin fees/delivery to process each order, their annual ordering cost is ₹6,000. If they ordered all 1,200 at once, the ordering cost drops to ₹500, but their wine cellar would overflow (high holding cost).
Annual Demand (A) = 10,000 units.
Order Size (Q) = 2,000 units per order.
Number of Orders per Year: 10,000 ÷ 2,000 = 5 orders.
Cost per Order (O) = ₹1,500.
Total Annual Ordering Cost: 5 orders × ₹1,500 = ₹7,500.
- Identify total annual requirement of raw materials.
- Determine the batch size/quantity being ordered.
- Divide demand by batch size to find the Number of Orders placed per year.
- Multiply the number of orders by the fixed administrative cost triggered by each order.
| Ordering Cost vs. Holding Cost | At the Economic Order Quantity (EOQ), Total Annual Ordering Cost will exactly equal Total Annual Holding Cost. This mathematically proves costs are minimized. |
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9 Out-of-Pocket Cost
| Category | Decision Making / Cash Flow Analysis |
|---|---|
| Best Used In | Short-term liquidity decisions, Make or Buy |
| Key Formula | Total Costs − Non-Cash Items (Depreciation/Amortization) |
| Exam Importance | Medium |
Out-of-Pocket Costs are those specific expenses that require an immediate or near-term outflow of actual cash from the business to complete a decision or project.
This concept explicitly strips away non-cash accounting entries, most notably Depreciation. For managers facing severe cash flow shortages, deciding whether to accept a project often depends strictly on whether the cash coming in covers the out-of-pocket cash going out, ignoring accounting book-value losses.
- Accepting special orders during an economic recession
- Capital Budgeting (calculating initial cash outlay)
- Working Capital planning
A machine has a total running cost of ₹500/hour, which includes ₹200 for electricity/labour and ₹300 for depreciation. A client offers ₹300 per hour to rent the machine. Normally, this is a ₹200 loss. However, the Out-of-Pocket cost is only ₹200. Taking the deal generates a positive net cash flow of ₹100, which is highly relevant if the business is struggling to pay payroll.
Total Estimated Cost of Special Job:
Raw Material: ₹10,000
Direct Wages: ₹5,000
Allocated Depreciation: ₹3,000
Total Accounting Cost: ₹18,000.
Out-of-Pocket Cost: ₹10,000 + ₹5,000 = ₹15,000 (Depreciation is ignored as no cash leaves the bank).
- List all costs associated with a decision.
- Identify and eliminate any depreciation on existing assets, amortization of goodwill, or allocated sunk costs.
- Sum up the remaining items (materials, new labour, extra power).
- Use this total to ensure the project doesn’t drain the company’s cash reserves.
| Out-of-Pocket Cost vs. Imputed Cost | Out-of-pocket requires actual cash leaving the business. Imputed cost (like interest on owner’s equity) uses zero cash. They are exact opposites. |
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11 Optimum Product Mix
| Category | Marginal Costing / Decision Making |
|---|---|
| Best Used In | Maximizing profit under resource constraints |
| Key Formula | Rank by Contribution per Limiting Factor |
| Exam Importance | Extremely High |
Optimum Product Mix is the specific combination and quantity of various products a company should manufacture to generate the absolute maximum possible total profit, especially when facing a shortage of resources.
If a company makes Products A, B, and C, but only has 10,000 machine hours available, they cannot fulfill all market demand. They must use Marginal Costing principles to formulate a priority list, producing the most efficient product first until demand is met, then moving to the second, until the 10,000 hours are gone.
- Production planning during raw material shortages
- Maximizing ROI on bottleneck machinery
- Short-term strategic sales planning
An electronics factory can make Laptops (Contribution ₹5,000, takes 5 hrs) and Tablets (Contribution ₹2,000, takes 1 hr). The manager calculates that Tablets generate ₹2,000 per hour, while Laptops only generate ₹1,000 per hour. The Optimum Product Mix dictates making maximum Tablets to satisfy market demand before dedicating any remaining hours to Laptops.
Constraint: 50,000 kg of Material available.
Product X: Demand 10,000 units. Cont. per kg = ₹10. (Needs 2kg/unit).
Product Y: Demand 5,000 units. Cont. per kg = ₹15. (Needs 4kg/unit).
Ranking: Rank 1 is Product Y (Higher Cont/kg).
Allocation: Make all 5,000 of Y (Uses 20,000 kg). Remaining 30,000 kg goes to Product X. Make 15,000 units of X. (This is the Optimum Mix).
- Identify the limiting factor (Key Factor).
- Calculate Contribution per unit for all products.
- Divide Contribution by the Key Factor requirement to establish Ranking.
- Allocate the scarce resource to Rank 1 up to its maximum market demand.
- Allocate remaining resources to Rank 2, then Rank 3, until resources are fully exhausted.
| Optimum Mix vs. Break-Even Mix | Break-even mix finds the minimum required to survive. Optimum mix finds the ceiling to maximize profit under constraints. |
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12 Operation Costing
| Category | Costing Methods |
|---|---|
| Best Used In | Mass production of standardized goods |
| Key Formula | Hybrid of Job and Process Costing |
| Exam Importance | Medium |
Operation Costing is a refinement of Process Costing. It is used when production consists of a series of repetitive, standardized mechanical operations, but the materials applied might differ slightly across different product batches.
Think of it as a hybrid. The conversion costs (labor and overhead) are identical for every unit because the machine operations are the same (like Process Costing). However, the direct materials can be traced specifically to different batches (like Job Costing).
- Clothing manufacturing (same sewing operation, different fabrics)
- Shoe manufacturing (same gluing operation, different leathers)
- Electronics assembly lines
A clothing factory makes 1,000 cotton shirts and 1,000 silk shirts. The cutting and sewing operations take the exact same time and effort for both, so the conversion cost is averaged across all 2,000 shirts (Operation Costing). However, the silk material is costed directly only to the silk batch, ensuring accurate pricing without overly complex accounting.
Batch 1 (Standard Jeans): Material = ₹50,000.
Batch 2 (Premium Jeans): Material = ₹90,000.
Operation 1 (Dyeing) Conversion Cost: ₹20,000 (Split evenly based on units processed).
The cost accountant treats the Dyeing operation as a cost center, but keeps material costs segregated by batch.
- Identify distinct physical operations (Cutting, Welding, Polishing).
- Accumulate labor and overheads for each Operation (Cost Center).
- Divide the Operation Cost by total equivalent units passing through it to find the conversion rate.
- Add the specific raw material cost to the absorbed operation cost for each specific product line.
| Operation Costing vs. Process Costing | In pure Process Costing, even the materials are homogenized and averaged (e.g., refining oil). Operation Costing allows for distinct materials while averaging the mechanical labor. |
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13 Output Costing (Single / Unit Costing)
| Category | Costing Methods |
|---|---|
| Best Used In | Mines, Quarries, Brick-making, Cement |
| Key Formula | Total Cost of Production ÷ Total Units Produced |
| Exam Importance | Medium |
Output Costing (also known as Single or Unit Costing) is the simplest method of cost accounting. It is used exclusively by industries producing a single, continuous, identical product where every unit is exactly the same as the next.
Because there is only one product, there is no need to apportion overheads between different departments or jobs. All costs incurred during the period are simply dumped into one bucket and divided by the total output to find the cost per unit.
- Coal mining and oil extraction
- Brick kilns and cement factories
- Flour mills and sugar factories
A brick kiln produces 10 Lakh bricks in a month. They spend ₹5 Lakhs on clay, ₹2 Lakhs on labour, and ₹1 Lakh on coal for the fire. The accountant doesn’t need complex allocation matrices. They simply take the total ₹8 Lakhs, divide it by 10 Lakh bricks, and determine the unit cost is ₹0.80 per brick.
A coal mine incurs the following in March:
Materials: ₹50,000 | Labour: ₹1,50,000 | Overheads: ₹50,000.
Total Cost = ₹2,50,000.
Output = 5,000 Tons of Coal.
Cost per Ton = ₹2,50,000 ÷ 5,000 = ₹50/Ton.
- Accumulate all Direct Materials, Direct Labour, and Direct Expenses.
- Add all Factory, Admin, and Selling Overheads.
- Prepare a standard Cost Sheet showing Total Cost.
- Add a secondary column to the Cost Sheet showing “Cost Per Unit” by dividing every line item by the total output volume.
| Output Costing vs. Job Costing | Job costing handles unique, custom orders (a bespoke wedding dress). Output costing handles millions of identical clones (a brick). |
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14 Obsolescence Cost
| Category | Inventory Management / Material Costing |
|---|---|
| Best Used In | Technology, Fashion, Perishables |
| Key Formula | Book Value of Inventory − Scrap Value |
| Exam Importance | Medium |
Obsolescence Cost is the financial loss a company suffers when its inventory (raw materials or finished goods) loses value because it is no longer desired by the market, usually due to technological advancements, changes in fashion, or new regulations.
It is a major component of Holding Cost (Carrying Cost). Unlike physical deterioration (spoilage), an obsolete item might be in perfect physical condition, but it is economically dead. In costing, extreme obsolescence requires writing down the inventory value and charging the loss to the P&L.
- Calculating accurate EOQ carrying cost percentages
- Valuing inventory under Ind AS 2 (Lower of Cost or NRV)
- Justifying transitions to Just-In-Time (JIT) manufacturing
A smartphone manufacturer has 10,000 units of “Phone Model 10” in the warehouse. Apple releases the iPhone 15. Suddenly, no one wants Model 10. The phones cost ₹15,000 to make, but can now only be sold to recyclers for ₹2,000. The ₹13,000 gap per phone is the Obsolescence Cost.
Purchase price of component = ₹1,000.
Interest on Capital = 10% p.a. Warehouse Space = 2% p.a. Risk of Obsolescence = 8% p.a.
Total Carrying Cost Percentage = 20%.
Holding Cost (C) used in EOQ = 20% of 1,000 = ₹200. High obsolescence forces the company to order in smaller batches.
- Identify slow-moving or non-moving items using FSN analysis.
- Determine the current market value (NRV) of these items.
- If NRV is lower than Cost, write down the inventory.
- Treat abnormal obsolescence (sudden tech shift) as a P&L period loss, not a product overhead, to avoid skewing current manufacturing costs.
| Obsolescence vs. Spoilage/Deterioration | Spoilage means the item physically rotted or broke. Obsolescence means the item works perfectly, but the market moved on. |
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15 Overhead Total Variance
| Category | Standard Costing |
|---|---|
| Best Used In | Executive summary of factory overhead control |
| Key Formula | Absorbed Overhead − Actual Overhead |
| Exam Importance | High |
Overhead Total Variance is the master variance for all indirect factory costs. It represents the total difference between the standard overhead recovered (absorbed) based on actual output, and the actual overhead incurred during the period.
It is mathematically identical to “Under or Over-Absorption of Overheads.” A Favorable variance means the factory absorbed more overhead into its products than it actually spent (a gain). An Adverse variance means the factory spent more than it absorbed (a loss).
- Reconciling standard costing P&L to actual P&L
- Acting as the parent variance to be split into Expenditure and Volume variances
- Evaluating overall cost center performance
The standard allows ₹50 of overhead per unit. The factory makes 1,000 units, “absorbing” ₹50,000. At month end, the bills for rent, electricity, and indirect labour total ₹52,000. The Overhead Total Variance is ₹2,000 Adverse. Management must now dig deeper into sub-variances to find out why.
Standard Hours for Actual Output = 4,000 hrs.
Standard Overhead Rate = ₹10/hr.
Absorbed Overhead = 4,000 × 10 = ₹40,000.
Actual Overhead Incurred = ₹38,000.
Total Variance = 40,000 – 38,000 = ₹2,000 Favorable.
- Find the Actual Output in units.
- Determine how many hours should have been taken to make that output (Standard Hours).
- Multiply by the Standard Rate to find the Absorbed Overhead.
- Subtract the absolute total Actual Overhead incurred.
| Total Variance vs. Sub-Variances | Total Variance = Expenditure Variance (Spending issue) + Volume Variance (Output issue). You must calculate the parent first to check the math of the children. |
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16 Overhead Volume Variance
| Category | Standard Costing (Fixed Overheads) |
|---|---|
| Best Used In | Measuring the cost of unused capacity |
| Key Formula | (Actual Output − Budgeted Output) × Standard Fixed Rate |
| Exam Importance | Very High |
Overhead Volume Variance applies strictly to Fixed Overheads. It isolates the gain or loss caused entirely by the factory producing more or fewer units than originally budgeted, regardless of whether spending changed.
Because fixed costs (rent) don’t change, the only way to “recover” them is by producing units. If you budget to make 10,000 units to cover the rent, but only make 8,000, you have a shortfall in recovery. This variance puts a dollar figure on that exact shortfall.
- Evaluating Production Department output performance
- Isolating the financial impact of strikes or machine breakdowns
- Splitting into Capacity, Calendar, and Efficiency variances
A factory rents a building for ₹1 Lakh/month, planning to make 10,000 tables (₹10 rent per table). They only make 9,000 tables. They only “absorbed” ₹90,000 of the rent. The missing ₹10,000 is the Volume Variance (Adverse). The factory manager must explain why production fell short of the 10,000 target.
Budgeted Fixed Overhead = ₹50,000. Budgeted Output = 5,000 units. (Standard Rate = ₹10/unit).
Actual Output = 5,200 units.
Absorbed Fixed OH = 5,200 × 10 = ₹52,000.
Volume Variance = Absorbed (52k) – Budgeted (50k) = ₹2,000 (Favorable).
They produced 200 extra units, recovering an extra ₹2k against fixed costs.
Shortcut: (Actual Output Units − Budgeted Output Units) × Std Fixed Rate per Unit
- Calculate the Standard Fixed Overhead Rate per unit.
- Compare the Actual Output against the original Budgeted Output.
- If Actual > Budgeted, it’s Favorable (you produced more than expected).
- Multiply the difference in units by the Standard Fixed Rate.
| Volume Variance vs. Expenditure Variance | Volume variance happens because output changed. Expenditure variance happens because the landlord raised the rent. They measure entirely different failures. |
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17 Overhead Expenditure Variance
| Category | Standard Costing |
|---|---|
| Best Used In | Evaluating spending control against the budget |
| Key Formula | Budgeted Overhead − Actual Overhead |
| Exam Importance | Very High |
Overhead Expenditure Variance (also known as Spending or Budget Variance) isolates the financial impact of simply spending more or less cash on overhead items than what was authorized in the original budget.
It completely strips away the effects of production volume. It simply asks: “Did the electricity rates go up? Did the landlord raise the rent? Did we pay supervisors too much overtime?” It holds the department managers accountable for their checkbooks.
- Expense control and accountability
- Analyzing inflation impacts on fixed costs
- Isolating spending issues from production efficiency issues
A factory budgets ₹1,00,000 for monthly rent. The landlord suddenly increases the rent to ₹1,10,000. The ₹10,000 difference is an Adverse Expenditure Variance. It has nothing to do with how many units the factory made; it is purely a price/spending issue.
Budgeted Fixed Overhead = ₹2,00,000.
Actual Fixed Overhead Paid = ₹2,15,000.
Expenditure Variance = 2,00,000 – 2,15,000 = ₹15,000 (Adverse).
Notice that Output Units are completely ignored in this specific calculation.
Variable OH Expenditure Variance = (Actual Hours × Std Variable Rate) − Actual Variable OH
- Identify the original Budgeted amount for the overhead (For Fixed OH, use the flat budget amount. For Variable OH, flex the budget to Actual Hours).
- Identify the total Actual cash paid for that overhead.
- Subtract Actual from Budgeted. Positive is Favorable; Negative is Adverse.
| Expenditure Variance vs. Volume Variance | Expenditure = “Did the bills go up?” Volume = “Did we make enough units to pay the bills?” Sum them together to get Total Fixed Overhead Variance. |
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18 Operating Leverage
| Category | Cost-Volume-Profit / Financial Strategy |
|---|---|
| Best Used In | Risk and return analysis of cost structures |
| Key Formula | Contribution ÷ EBIT (Operating Profit) |
| Exam Importance | High |
Operating Leverage is a multiplier that measures how sensitive a company’s Operating Profit (EBIT) is to a change in Sales volume. It is entirely driven by the ratio of Fixed Costs to Variable Costs in the company’s cost structure.
A company with high fixed costs (like an airline) has High Operating Leverage. Once they pass break-even, every extra ticket sold drops almost pure profit to the bottom line. However, if sales drop slightly, profits will crash catastrophically. It is a double-edged sword of risk and reward.
- Deciding whether to automate a factory (increasing fixed costs) or use manual labour (increasing variable costs)
- Forecasting profit jumps during economic booms
- Assessing bankruptcy risk during recessions
A software company has ₹10 Lakhs in fixed costs (server rent, dev salaries) and ₹0 variable costs. Their Operating Leverage is massive. If sales increase by 10%, their profits might jump by 50%. A consulting firm has high variable costs (consultant hourly pay) and low fixed costs. If their sales jump 10%, profits only jump 10%.
Sales = ₹1,00,000. Variable Costs = ₹40,000. Contribution = ₹60,000.
Fixed Costs = ₹40,000. EBIT (Profit) = ₹20,000.
Operating Leverage = 60,000 ÷ 20,000 = 3.0.
Meaning: If Sales increase by 10%, Profit will increase by 30% (10% × 3.0).
% Change in Profit = % Change in Sales × DOL
- Prepare a Marginal Cost Statement (Sales – VC = Cont. | Cont – FC = Profit).
- Divide the Contribution by the final Profit.
- The resulting multiplier (e.g., 4x) tells you the magnification effect of sales changes on profits.
- The closer the firm is to its Break-Even Point, the higher the leverage multiplier will be.
| Operating Leverage vs. Financial Leverage | Operating leverage involves Fixed Operating Costs (Rent, Depreciation). Financial Leverage involves Fixed Financial Costs (Interest on Debt). Combined, they create Total Leverage. |
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19 Overhead Efficiency Variance
| Category | Standard Costing (Fixed Overheads) |
|---|---|
| Best Used In | Measuring the overhead cost of slow workers |
| Key Formula | (Standard Hours − Actual Hours) × Std Fixed Rate |
| Exam Importance | High |
Overhead Efficiency Variance is a sub-variance of Volume Variance. It measures the amount of fixed overhead that was over-absorbed or under-absorbed purely because the workforce operated faster or slower than the standard allowed time.
If workers take 12 hours to do a 10-hour job, the company is losing money on direct labour wages. However, they are ALSO losing money because the factory lights, rent, and supervisor time (Fixed Overheads) were consumed for an extra 2 hours with no extra output to show for it.
- Calculating the true, fully-loaded cost of labour inefficiency
- Detailed sub-analysis of Fixed Overhead Volume Variance
- Performance appraisal of production floor managers
Standard allows 5 hours per car. Factory makes 100 cars (Standard Hours = 500). Workers actually took 600 hours because they were chatting. The 100 wasted hours means 100 hours of factory rent was wasted. The accountant multiplies the 100 wasted hours by the fixed overhead rate to show management the hidden cost of slow work.
Standard Hours for Actual Output (SH) = 1,000 hrs.
Actual Hours Worked (AH) = 1,200 hrs.
Standard Fixed Overhead Rate = ₹50/hr.
Efficiency Variance = (1,000 – 1,200) × 50 = ₹10,000 (Adverse).
Workers were slow, causing a ₹10k loss in overhead absorption efficiency.
- Determine the output actually achieved.
- Calculate how many hours that output should have taken (SH).
- Compare to how many hours it actually took (AH).
- If AH > SH, it’s Adverse (you were slow).
- Multiply the hour difference by the Standard Fixed Overhead Rate.
| OH Efficiency Variance vs. Labour Efficiency Variance | They use the exact same hour difference (SH – AH). The only difference is the multiplier. Labour Efficiency multiplies by the Wage Rate. OH Efficiency multiplies by the Fixed OH Rate. |
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20 Outsourcing (Strategic Make vs. Buy)
| Category | Strategic Cost Management |
|---|---|
| Best Used In | Long-term supply chain and core competency planning |
| Key Formula | Relevant Cost to Make vs. Supplier Quote + Qualitative Factors |
| Exam Importance | Very High (Case Studies) |
Outsourcing is the strategic delegation of non-core operations or manufacturing processes to an external third-party vendor. In costing, it is the advanced, long-term application of the “Make or Buy” decision.
While a simple Make/Buy decision might look at saving ₹5 per unit today based on marginal costs, Strategic Outsourcing looks at the long-term impact on fixed costs. Can we sell our factory? Can we fire the HR team? Will the supplier steal our trade secrets?
- Business Process Outsourcing (BPO) for IT, Payroll, or Customer Service
- Divesting manufacturing plants to become a pure “design and marketing” firm (e.g., Nike, Apple)
- Converting Fixed Costs into Variable Costs to reduce Operating Leverage
A bank processes its own payroll. It requires ₹50 Lakhs in fixed salaries and software licenses yearly. An external BPO offers to do it for ₹300 per employee per month (Variable Cost). The bank calculates the crossover point. By outsourcing, they destroy their fixed costs, lower their operating leverage, and save money.
Quantitative: Internal Variable Cost = ₹100/unit. Supplier Quote = ₹110/unit. Math says: MAKE.
Qualitative: The supplier has a new patented robotic process that reduces defects by 90%, and outsourcing frees up the factory floor to launch a highly profitable new product.
Decision: OUTSOURCE. The strategic value overrides the ₹10 marginal loss.
- Identify all internal Marginal Costs that will disappear if outsourced.
- Identify all specific Fixed Costs that can be completely eliminated (Avoidable Fixed Costs) if outsourced.
- Add the expected profit from using the newly empty factory space for something else (Opportunity Cost).
- Compare this total against the supplier’s long-term contract price.
- Apply Qualitative filters (Quality, Secrecy, Delivery reliability).
| Outsourcing vs. Sub-Contracting | Sub-contracting is usually temporary or for a specific part of one job (hiring an electrician for a house build). Outsourcing is a permanent shift of an entire function to an outside party. |
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