I often hear the statement “Our problem is caused by lack of capacity?” and this is usually followed by a heated debate (i.e. an arugment) about how to get more resources to solve the “capacity problem”: The protagonists are usually Governance who start the debate by raising a safety or quality problem; Operations who are tasked to resolve the problem and Finance who are expected to pay.
But what are they talking about? What exactly is “Capacity”? The reason I ask is because the word is ambiguous – it has several meanings – and unless the precise meaning is made explicit then individuals may unconsciously assume different interpretations and crossed-wires, confusion and conflict will ensue.
From the perspective of a process there are at least two distinct meanings that must not be confused: one is flow capacity and the other is inventory capacity. To give an example of the distinction consider your household plumbing system: the hot water tank has a capacity that is measured in the volume of the tank – e.g. in litres; the pipe that leads from the tank to your tap has a capacity that is measured by the flow through the pipe – e.g. in litres per minute. These are clearly NOT the same; they are related by time: A 50 litre capacity tank connected to a 5 litre per minute capacity pipe will empty in 10 minutes. So when you are talking about “capacity” be sure to be explicit about which form you mean … volume or flow; static or dynamic; inventory or activity. It will avoid a LOT of confusion!!