1. Introduction and Objectives
Cost accounting provides the quantitative basis for organizational planning, control, and decision-making. Unlike financial accounting, which reports historical performance to external stakeholders, cost accounting serves internal managers. This lesson establishes the standard definitions mandated by the IMA (USA) and CIMA (UK/Europe) to ensure uniform communication across multinational enterprises.
2. Core Definitions and Conceptual Framework
  • Cost: The monetary measure of resources sacrificed or foregone to achieve a specific objective, such as manufacturing a product or rendering a service.
  • Cost Object: Any item, activity, or organizational unit for which a separate measurement of costs is desired.
    • Examples: A physical product (an iPhone), a service (a routine medical check-up), a project (building a bridge), a customer (a major retail account), or a department (the marketing division).

  • Cost Unit: A unit of product, service, or time in relation to which costs may be ascertained or expressed. It serves as the standard denominator for pricing and efficiency comparisons.
    • Examples: Cost per passenger-kilometer (aviation), cost per bed-night (hospitality), cost per kilowatt-hour (utilities).

  • Cost Centre: A production or service location, function, activity, or item of equipment for which costs are accumulated. It represents the smallest organizational subunit where responsibility for costs is isolated.
    • Production Cost Centre: Directly engaged in manufacturing (e.g., the assembly line).
    • Service Cost Centre: Provides support to other departments (e.g., information technology, maintenance).

  • Cost Driver: Any factor or variable that causes a direct, causal change in the total cost of an activity over a specific time horizon.
    • Examples: Machine hours, number of setups, engineering change orders, or delivery miles driven.

3. Real-World Application Example
A global logistics company like DHL defines its Cost Object as a specific delivery route. Its Cost Unit is the cost per package delivered. The Cost Centre is the local sorting hub, and the Cost Drivers include the number of delivery stops and total fleet fuel consumption.
 
Next