Workflow Design: Horizontal Handling vs. Vertical Handling

Here’s a follow up to a previous post of the one point lesson on operational availability vs. rate of operation. A reader pointed out that pictures and not just words would be helpful, so in answer to a related question about multi-process handling, here are a few words plus two pictures.
Multi-machine handling is when a single operator runs multiple machines of a similar type. In this example of shaft machining, the lathe operator will produce turned parts. The mill operator will then mill all of the turned parts, etc. One operator is running 4 lathes, another runs mills, another drills, etc.

Multi-machine handling is also called horizontal handling, as you can see that the operators’ responsibilities on the chart are assigned horizontally (side to side on the chart) by machine or process type.
In multi-process handling the equipment would be arranged in process sequence (10 > 20 > 30 > 40) by product family. In this example one operator runs four machines, one lathe, one mill, one drill and one tapping machine and makes a completed shaft.

Multi-process handling is also called vertical handling, as you can see that the operators’ responsibilities are assigned vertically (top to bottom on the chart) for a particular part or part family.
This idea applies not only to machine work but any process, whether it is assembly, bill payment, or patient care. The thinking behind this is to look at the whole process from the viewpoint of what is best for the customer instead of from what is best for the functional unit or department performing the process. The more that processes are connected one-to-one, the shorter the time is through the process safety, quality, delivery and cost are improved.