The sequence by which a person performs any task is directly related to the efficiency (and correctness) with which the task is performed. In many cases, safety is not an issue, but tasks performed in an incorrect sequence must often be repeated, leading to duplicated effort and wasted time.
When making a setup, for example, if the workholding device is not squared with the table prior to measuring the program zero point, it will mean the program zero point measurement must be repeated (if and) when the setup person determines that they forgot to square the workholding device. If this step is missed, of course, scrap parts will be machined – and even more duplicated effort will be required when the setup person eventually figures out what is wrong.
But there are times, of course, when safety is directly related to the sequence by which a given task is performed. Forgetting to attach and/or adjust the coolant lines prior to running a program for the first time could lead to an injured operator if coolant is sprayed on them – especially if it hits them in the eyes. Failure to fully tighten the workholding device to the table prior to running a part could be disastrous. Failure to scan to the appropriate command in a program prior to rerunning a tool could cause a serious crash.
The list goes on and on. Obviously training has a lot to do with safety. Well-trained setup people and operators will be less likely to perform tasks out of sequence.
But why leave it up to setup people and operators to determine the order by which tasks should be completed – especially when efficiency and safety issues are at stake? Providing your people with safe operating procedures – and ensuring that the procedures are followed – will minimize the potential for tasks to be performed out of sequence.
I recommend creating an operation handbook for each machine. In this handbook, you can document procedures to do everything from turning the machine on to turning it off. This will simplify the tasks related to running CNC machines, ensure that tasks are performed efficiently, and – most importantly – minimize the potential for mistakes that can lead to injured people.