Cost behaviour

In this lesson

1. 0:00 Cost behaviour classification fundamentals
2. 0:32 Fixed costs and factory rent example
3. 1:28 Stepped costs and capacity thresholds
4. 3:35 Semi-variable costs structure and utilities
5. 4:39 Variable costs and piece rate systems
6. 5:35 Graphing fixed costs and economies of scale
7. 7:21 Visualising stepped costs on graphs
8. 8:37 Semi-variable cost graphs and analysis
9. 10:34 Variable cost graphs and cost per unit

About this lesson

You'll explore four key cost types: fixed costs (unchanged by production volume), stepped costs (fixed until a capacity threshold is reached), semi-variable costs (containing both fixed and variable elements), and variable costs (rising directly with production). Understanding these distinctions is essential for budgeting, variance analysis, and predicting how costs will change as your business activity fluctuates. The lesson uses practical examples and visual graphs to make each cost behaviour concrete. Fixed costs like factory rent remain constant regardless of output, but their cost per unit decreases as you produce more—a concept known as economies of scale. Stepped costs jump when you cross capacity thresholds, such as needing to rent additional equipment. Semi-variable costs, like utility bills, combine a standing charge (fixed element) with usage charges (variable element), making them the trickiest to manage because you need to isolate each component. Variable costs, such as piece-rate worker wages, scale directly with production and are straightforward to forecast once you know the cost per unit. By the end of this lesson, you'll be confident reading cost behaviour graphs, identifying which classification applies in exam scenarios, and using this knowledge to support budgeting and management accounting decisions. This foundational understanding will support your performance across Performance Management, Advanced Performance Management, and Strategic Business Leader papers.

Duration: 12m