GlossaryKind of term: Manufacturing termOperation
What is an operation?
An operation is a discrete step in making a part, such as face milling, drilling or reaming, with its own tool or work centre and its own time.
Pocketing, tapping and parting off are operations too. Each one creates or changes one or more features. It is neither the feature nor the requirement: on a ⌀12 H7 hole, the hole is the feature, H7 the requirement, and drilling and reaming are the operations.
How finely are operations divided?
How finely operations are divided depends on the level of planning. In an ERP routing an operation is usually one step at one work centre, such as sawing, milling, heat treatment or inspection, with a setup time and a time per piece. In a CAM program an operation is one toolpath with one tool and one strategy, so a single routing step can hold dozens. Which operations a feature needs follows from its requirement (size, form, roughness), the material, the tooling and the sequence: a tight fit may take drilling and reaming or drilling and boring, a pocket a roughing and a finishing pass.
How does an operation work in practice?
An operation's time is cutting time plus non-cutting time: rapid moves, tool changes, probing. An estimate built up per operation shows where the time goes; a forgotten operation, such as the reaming pass on a fitted hole, leaves the machining time short without anyone noticing. Times per operation can later be compared with actuals, provided the hours are booked at the same level. Whether deburring, inspection or cleaning count as operations in their own right is a matter of shop convention.
What is an operation often confused with?
An operation is not a setup: one setup usually holds several operations, while a single routing operation can span several setups. It is not a feature either: the pocket is in the part, roughing and finishing are what you do to it.
How do you see an operation in Blake?
In the Blake estimate, machining is a line of its own beside material, finishing, setup and programming, per piece and per batch. The time is labelled as an estimate. Correcting an estimate line requires a reason, and who changed what and when stays visible. More on estimating.
Frequently asked questions
How many operations does a part need?
It varies with the level: a handful of steps in the routing, one per toolpath in the CAM program. The count follows from the features, their requirements, the material and the setups. A fitted hole, for example, usually takes more than one operation.
Why are operations numbered in tens?
It is a common routing convention: 10, 20, 30. It leaves room to insert a step later, such as 25 for deburring, without renumbering the rest. No standard requires it; it is established practice in manufacturing engineering and ERP.
Is deburring a separate operation?
It depends. Deburring with a tool in the machine usually belongs to the machining operation. Hand deburring, vibratory finishing or blasting is normally a step of its own in the routing, with its own time or as a subcontract line.