Job, Batch, Contract and Service Costing

Introduction and context

Costing systems translate resource consumption into information about products, projects, services and customers. The appropriate system depends principally on the degree of product standardisation, the separability of jobs, the duration of production and the way in which output is measured. Job costing is suitable when work is customised and separately identifiable; batch costing applies when identical units are produced as a group; contract costing addresses large, long-term undertakings; and service costing measures the cost of providing intangible or semi-intangible services.

These methods are not isolated techniques. They are applications of the same cost-accounting logic: direct costs are traced to a cost object, indirect costs are allocated or absorbed using rational bases, work in progress is measured, and cost information is compared with revenue, budgets and performance expectations. At postgraduate level, the central issue is not merely calculating cost but designing a system that produces decision-useful, auditable and strategically relevant information.

Learning objectives

After studying this chapter, the learner should be able to:

1. Explain the purpose and design of job, batch, contract and service costing systems.
2. Calculate direct cost, overhead absorption, work-in-progress and profit for different cost objects.
3. Distinguish contract profit recognition from final contract profitability.
4. Select suitable cost units for service organisations.
5. Analyse limitations, behavioural consequences, digital developments and governance risks in customised and project-based costing.

1. The architecture of customised costing systems

A cost object is anything for which cost is measured—for example, a customer order, production batch, construction contract, patient episode, delivery route or consulting engagement. A cost driver is a factor that causes or significantly influences cost, such as labour hours, machine hours, purchase orders or kilometres travelled.

The basic structure is:

Direct material and direct labour can be economically traced to an individual job or contract. Indirect costs, such as supervision, depreciation, information technology and factory occupancy, are assigned through cost centres and overhead rates.

A conventional predetermined overhead rate is:

If activity is measured in labour hours, the rate has the unit currency per labour hour. If machine hours are used, it has the unit currency per machine hour. The rate should be calculated separately for materially different cost centres where processes, technology or cost behaviour differ.

The cost charged to a job is then:

This approach assumes that the selected activity base is sufficiently related to overhead consumption and that budgeted conditions are reasonably representative. Where activities are diverse, activity-based costing may use several cost pools and drivers rather than one blanket rate.

At period end, the difference between overhead absorbed and overhead incurred is an over- or under-absorption. Over-absorption occurs when absorbed overhead exceeds actual overhead; under-absorption occurs in the reverse situation. Material variances should be investigated and treated consistently under the organisation’s accounting policy.

2. Job costing

Nature and applications

Job costing accumulates costs for a separately identifiable job, order or assignment. Each job receives a job-cost sheet containing its identifying details, customer, specifications, dates, materials, labour, overhead and completion status. Typical applications include specialist engineering, printing, advertising, legal work, audit, software development, repair work and customised furniture.

The job-costing cycle is:

1. Authorise and code the job.
2. Issue materials against the job or record material requisitions.
3. Record employee time through time sheets or digital time capture.
4. Apply production or service overhead.
5. Record rework, scrap, subcontracting and change orders.
6. Compare accumulated cost with quotation, budget and revenue.
7. Transfer completed work to cost of sales or invoice the customer according to the contractual arrangement.

A job cost sheet may be represented as:

The job’s gross margin is:

The margin percentage on revenue is:

This differs from mark-up on cost:

For example, a job costing CU 80,000 and sold for CU 100,000 has a margin of CU 20,000, or 20% of revenue, but a mark-up of 25% on cost. Confusing these measures causes systematic pricing errors.

Worked example: job costing

A manufacturer estimates annual factory overhead of CU 1,200,000 and 30,000 machine hours. Job J17 uses direct materials of CU 18,000, 420 machine hours and direct labour costing CU 12,600. The predetermined machine-hour rate is:

Overhead applied to J17 is CU 16,800 (420 × CU 40). Total job cost is therefore:

If the quoted selling price is CU 60,000, gross margin is CU 12,600 and margin on revenue is 21%. The calculation is valid only if machine hours are a reasonable proxy for factory overhead consumption. If engineering design and procurement activities dominate cost, a single machine-hour rate may distort the result.

Work in progress in job costing

Incomplete jobs remain in work in progress (WIP). A job register should reconcile opening WIP, costs added, transfers to completed jobs and closing WIP:

WIP should be supported by job status, approved cost records and evidence of completion. Costs should not be transferred to completed output merely to improve reported performance.

3. Batch costing

Meaning and relationship with job costing

Batch costing is a form of job costing in which a batch of identical or substantially similar units is treated as one cost object. It is common in pharmaceuticals, garments, food processing, component manufacture and specialised printing. Costs are collected for the batch and then divided by the number of good units to determine unit cost.

The denominator must exclude defective units that cannot be sold as normal output. Normal process loss is usually incorporated into the expected cost of good output, whereas abnormal loss should be separately identified and investigated.

Economic batch quantity

Where a firm must decide how many units to produce in a batch, it may consider set-up and holding costs. A simplified economic batch quantity is:

where D is annual demand in units, S is set-up cost per batch, and H is annual holding cost per unit. The formula assumes relatively stable demand, constant set-up and holding costs, instantaneous replenishment for the basic model, and no significant quantity discounts or capacity constraints. It is a planning model, not a substitute for operational judgement.

Worked example: batch costing

A batch has the following costs: direct materials CU 24,000, direct labour CU 10,000 and production overhead CU 6,000. The batch contains 1,000 units, of which 20 are abnormal defects and 30 are normal loss. Good output is therefore 950 units. Total cost is CU 40,000, and cost per good unit is:

If abnormal defect cost is separately written off at CU 600, the cost assigned to good units would be CU 39,400 ÷ 950 = approximately CU 41.47, subject to the entity’s costing policy. The key requirement is consistency and transparent treatment of normal and abnormal loss.

4. Contract costing

Characteristics

Contract costing is used for large, non-repetitive undertakings that often extend over more than one accounting period. Construction, civil engineering, shipbuilding, major infrastructure, defence and complex information-system implementations are examples. Each contract is a distinct cost object, often performed at or near the customer’s site.

Important contract records include:

• contract price and approved variations;
• architect’s or engineer’s certificates;
• materials received, issued, returned or transferred;
• labour, plant and subcontractor costs;
• retention money and progress payments;
• escalation, claims, liquidated damages and incentives;
• estimated cost to complete; and
• physical progress and forecast completion date.

Direct contract costs commonly include site labour, materials, subcontractors, plant used on the contract and site supervision. General overhead should be allocated only when a rational and consistently applied basis exists.

Contract accounts and work in progress

A contract account normally records direct costs, attributable overhead, recognised profit or loss and the value of work certified. Work certified is the portion approved by the customer’s representative; work uncertified is completed work awaiting certification and is normally valued at cost, subject to applicable financial reporting requirements.

A simplified contract position is:

This is a management measure, not automatically the profit recognised in external financial statements. External reporting requires the applicable accounting framework, particularly rules concerning performance obligations, variable consideration, expected losses and satisfaction of obligations over time.

Profit recognition on incomplete contracts

For a contract that is substantially incomplete, management accounting texts traditionally use a conservative fraction of notional profit based on certified progress. A commonly taught convention is:

This convention is applicable only as an instructional or internal-control rule where the organisation has adopted it. It is not a universal financial reporting rule. The factor 2⁄3 reflects caution about uncertain future costs and cash collection; it must not override the relevant accounting standard.

When a contract is near completion, a more cautious convention may be:

Again, the exact policy must be documented. If a loss is expected on the whole contract, the expected total loss should be recognised promptly under the applicable reporting requirements; deferring it because the contract is incomplete is unacceptable.

Worked example: contract profitability

A contract has an agreed price of CU 10,000,000. Costs incurred to date are CU 6,400,000. Work certified is CU 8,000,000 and work uncertified costs CU 200,000. Cash received is 80% of work certified, or CU 6,400,000.

Notional profit is:

Using the traditional two-thirds convention, recognised profit is:

The contract’s forecast profit must still be calculated using the estimated total cost to complete. Suppose the estimated remaining cost is CU 2,900,000. Forecast total cost is CU 9,300,000 and forecast final profit is CU 700,000, not CU 1,800,000. This illustrates why cost-to-complete forecasting is more informative than relying on current certification.

Contract control and earned value

Project managers increasingly supplement accounting data with earned-value management. Three useful measures are:

• Planned value (PV): budgeted value of work scheduled.
• Earned value (EV): budgeted value of work actually completed.
• Actual cost (AC): actual cost of work performed.

Cost variance and schedule variance are:

Cost performance index and schedule performance index are:

These measures require a credible baseline, measurable work packages and consistent valuation of progress. A CPI below 1 indicates that actual cost exceeds the budgeted value of work completed. Earned value does not replace statutory revenue recognition or cash-flow analysis.

5. Service costing

Nature of service cost units

Services are often consumed as they are produced, cannot be stored economically and contain a substantial labour or capacity component. Cost systems therefore focus on operational cost units that reflect the service delivered. A cost unit may be simple, such as a passenger-kilometre, or composite, such as a patient-day or room-night.

A cost unit should be measurable, controllable, relevant to users and sufficiently stable for comparison. A composite unit must state its construction clearly. For example:

Average cost per passenger-kilometre is:

Worked example: transport service

A bus division incurs monthly operating costs of CU 900,000. It operates 30 buses, each travelling 6,000 kilometres per month. Average occupancy is 25 passengers per trip-equivalent kilometre. Passenger-kilometres are:

Average cost is CU 0.20 per passenger-kilometre (CU 900,000 ÷ 4,500,000). If occupancy falls to 20 passengers while distance and cost remain unchanged, passenger-kilometres become 3,600,000 and average cost rises to CU 0.25. The increase is not necessarily caused by operational inefficiency; it may reflect under-utilised capacity. Managers should therefore analyse both cost per unit and utilisation.

Composite and customer profitability

Service organisations should distinguish capacity-sustaining costs from transaction-level costs. A hospital, for example, may incur building and clinical leadership costs regardless of patient volume, while diagnostic tests and consumables vary with cases. Customer or service-line profitability can be analysed using resource consumption, but allocations should not be interpreted as precise causal truth when shared capacity is substantial.

6. Integrated illustrative case: Orion Engineering Services

Background

Orion Engineering Services designs and installs energy-control systems. It performs small customised jobs, produces standard sensor kits in batches, and undertakes multi-year industrial contracts. The company historically used one overhead rate based on direct labour hours.

Problem

Management discovered that small design-intensive jobs were undercosted, while repetitive installation work was overcosted. Contract forecasts also ignored remaining engineering effort, and service managers measured technician utilisation but not customer value.

Analysis

A review identified four activity pools: engineering design, procurement, installation supervision and administration. Appropriate drivers were design hours, purchase orders, site hours and contract value respectively. For a major contract, the team prepared a monthly cost-to-complete forecast and compared planned value, earned value and actual cost. For maintenance services, it introduced cost per resolved service call and first-time resolution rate alongside technician utilisation.

Approach and solution

Orion retained job-cost sheets for customised work, introduced batch sheets for sensor kits and created contract ledgers with approved variations, retention and forecast completion costs. It used separate overhead rates for engineering and installation rather than a single labour-hour rate. Digital time capture was linked to project codes, but entries required supervisor approval and periodic audit.

Outcome

The revised system revealed that several apparently profitable design jobs had margins below the company’s hurdle rate. It also showed that a contract with favourable invoicing was forecast to make a loss because late design changes would increase remaining costs. Service reporting identified that repeat visits, rather than low technician productivity, were the principal cost driver.

Learning points

The case demonstrates that costing-system design is a managerial choice with strategic consequences. Better causal drivers improve pricing and resource decisions, but no allocation system eliminates uncertainty. Forecasting, operational measures and professional judgement must accompany accounting records.

7. Governance, technology and contemporary developments

Costing information influences quotations, staff evaluation, bonuses and contract claims. Ethical risks include charging unrelated costs to a customer, manipulating progress estimates, recording premature completion, hiding abnormal waste and using arbitrary allocations to justify a predetermined commercial result. Strong governance requires segregation of duties, documented costing policies, approval of variations, audit trails and independent review of significant estimates.

Enterprise-resource-planning systems can integrate purchasing, payroll, inventory, time recording and project management. Mobile applications and Internet-of-Things devices can capture machine hours, kilometres and field-service activity. Artificial intelligence may classify transactions, predict cost-to-complete and identify unusual spending patterns. However, AI outputs depend on reliable historical data and may reproduce coding bias or obscure judgement. Human review, explainability, access controls and model monitoring remain necessary.

Contemporary costing increasingly incorporates:

• target costing and life-cycle costing for engineered products;
• carbon and environmental cost per job or service unit;
• time-driven activity-based costing for capacity analysis;
• customer profitability and contract portfolio analysis; and
• rolling forecasts rather than static annual budgets.

A sophisticated system should report not only cost incurred but also unused capacity, quality cost, schedule risk, carbon impact, rework and expected cost to complete.

8. Limitations and best-practice principles

No costing method is universally superior. Job costing can become administratively expensive and may encourage employees to record time according to budget expectations rather than reality. Batch costing may conceal differences between production runs. Contract costing is highly sensitive to estimates, claims and physical-progress measurement. Service costing may produce misleading averages when service complexity varies widely.

Best practice includes:

1. Define the cost object and purpose before selecting the method.
2. Trace costs directly wherever economically feasible.
3. Select drivers using cause-and-effect evidence, not convenience alone.
4. Separate normal operating cost from abnormal loss, rework and exceptional items.
5. Reconcile subsidiary records with the general ledger.
6. Update cost-to-complete estimates frequently on long-term work.
7. Report both financial and operational measures.
8. Test rates for capacity utilisation and changing technology.
9. Document assumptions, estimates and approval responsibilities.
10. Review the system’s behavioural and ethical consequences.

Chapter Summary

Job costing accumulates cost for a distinct customised assignment, while batch costing treats a group of similar units as one cost object and divides cost by good output. Contract costing applies to large, long-term undertakings and requires disciplined treatment of certification, retention, variations, work in progress and cost-to-complete estimates. Service costing measures resources against operational units such as passenger-kilometres, patient-days or resolved cases.

Across all four methods, reliable results depend on clear cost objects, economically traceable direct costs, rational overhead drivers, controlled WIP records and consistent treatment of losses. Traditional contract-profit conventions are useful instructional tools but do not replace applicable financial reporting standards. Modern systems combine accounting data with earned value, capacity, quality, customer, environmental and technology-enabled measures. The professional accountant must therefore evaluate not only arithmetic accuracy but also causality, governance, uncertainty and decision relevance.

Key Terms

Cost object: Anything for which cost is measured.

Cost driver: A factor that causes or influences cost.

Job costing: Cost accumulation for an individually identifiable job or order.

Job-cost sheet: A record of materials, labour, expenses and overhead assigned to a job.

Batch costing: Costing a group of similar units as one cost object.

Economic batch quantity: Production batch size that balances set-up and holding costs under specified assumptions.

Contract costing: Costing of large, long-term, separately identifiable undertakings.

Work in progress: Incomplete output carrying accumulated cost at a reporting date.

Work certified: Contract work approved by the customer’s authorised representative.

Retention money: Amount withheld by a customer until contractual conditions are satisfied.

Notional profit: Provisional profit calculated on work performed to date.

Cost-to-complete: Estimated future cost required to finish a job or contract.

Service cost unit: Quantified unit of service output used to measure cost.

Composite cost unit: A cost unit combining two or more dimensions, such as passenger-kilometres.

Overhead absorption: Assignment of indirect cost to a cost object using an absorption rate.

Over-absorption: Absorbed overhead exceeding actual overhead incurred.

Earned value: Budgeted value of work actually completed.

Capacity utilisation: Extent to which available productive capacity is used.

Target costing: Designing a product or service to achieve a required cost from market price and target profit.

Customer profitability: Analysis of revenue and resource consumption attributable to a customer or customer group.

Review Questions

Short Answer Questions

1. What is a cost object, and why is its definition important in job costing?
2. Distinguish margin percentage from mark-up percentage.
3. Why are abnormal losses normally identified separately in batch costing?
4. What is the purpose of a cost-to-complete estimate in contract costing?
5. Give two examples of composite service cost units.

Long Answer Questions

1. Explain the design and operation of a job-costing system, including materials, labour, overhead and work in progress.
2. Discuss the major accounting and managerial issues arising in long-term contract costing.
3. Compare job, batch, contract and service costing in terms of cost objects, output measurement and principal risks.
4. Explain how activity-based costing can improve the assignment of overhead in a multi-service organisation.
5. Evaluate the usefulness and limitations of earned-value measures in contract performance management.

Analytical / Application Questions

1. A customised job uses direct materials of CU 35,000, direct labour of CU 18,000 and 500 machine hours. The predetermined machine-hour overhead rate is CU 32. The selling price is CU 75,000. Calculate total cost, gross margin and margin percentage on revenue. Interpret the result.
2. A contract has a price of CU 15 million, costs incurred of CU 9 million, certified work of CU 11 million and uncertified work costing CU 300,000. Cash received is 75% of certified work. Calculate notional profit and, using the traditional two-thirds convention, provisional recognised profit. State two reasons why the result may not equal externally reported profit.
3. A hospital is choosing between patient-day, case-mix-adjusted discharge and clinical department cost units. Evaluate the advantages and limitations of each and recommend a measurement structure for strategic cost management.

Multiple Choice Questions with Answers

Question 1

Which costing method is most appropriate for a separately identifiable customised engineering order?

A. Process costing

B. Job costing

C. Marginal costing only

D. Uniform costing

Correct Answer: B. Job costing

Question 2

A batch costs CU 40,000 and produces 950 good units. What is the cost per good unit, approximately?

A. CU 40.00

B. CU 41.05

C. CU 42.11

D. CU 44.44

Correct Answer: C. CU 42.11

Question 3

If budgeted overhead is CU 900,000 and budgeted machine hours are 30,000, the predetermined overhead rate is:

A. CU 3 per machine hour

B. CU 30 per machine hour

C. CU 270 per machine hour

D. CU 930,000 per machine hour

Correct Answer: B. CU 30 per machine hour

Question 4

Which item is most directly associated with long-term contract costing?

A. Retention money

B. Economic order quantity

C. Equivalent units

D. Standard loss percentage only

Correct Answer: A. Retention money

Question 5

In earned-value analysis, a cost performance index below 1 generally indicates that:

A. Actual cost exceeds earned value

B. Earned value exceeds actual cost

C. The project is ahead of schedule

D. No cost information is available

Correct Answer: A. Actual cost exceeds earned value

Question 6

Which is a composite service cost unit?

A. One invoice

B. One employee

C. Passenger-kilometre

D. One cost centre

Correct Answer: C. Passenger-kilometre

Question 7

A job costs CU 80,000 and is sold for CU 100,000. Its margin percentage on revenue is:

A. 20%

B. 25%

C. 80%

D. 125%

Correct Answer: A. 20%

Question 8

Which condition most strongly supports the use of separate overhead rates?

A. All departments consume resources in identical proportions

B. Different activities have materially different cost drivers

C. The organisation has no indirect costs

D. All jobs use exactly the same machine hours

Correct Answer: B. Different activities have materially different cost drivers

Question 9

If a contract is expected to make an overall loss, the appropriate general response is to:

A. Defer the loss until completion

B. Recognise the expected loss promptly under the applicable requirements

C. Recognise profit on all certified work

D. Ignore remaining costs

Correct Answer: B. Recognise the expected loss promptly under the applicable requirements

Question 10

Which control best reduces the risk of premature contract-profit recognition?

A. Removing project codes

B. Independent review of progress and cost-to-complete estimates

C. Using only cash receipts as revenue

D. Recording all costs as administration

Correct Answer: B. Independent review of progress and cost-to-complete estimates