How to evaluate your DL manpower (1/2)

Today I want to discuss the topic, How to evaluate DL manpower. Normally it belong to IE's job scope, but we need to check IE's model fit MFG's status or not. I would like  to introduce the DL manpower count method, and how to increase DL working capability with you.

DL manpower's count have some models, MMR (Ｍan Machine ratio), Time study, Function allocate and so on. I will try to simply talk about it.

1. MMR (Man Machine ratio), it's the basic and simple way to evaluate the manpower you need. It's not a accuracy way to the detail. But it can help to to get a whole picture about your DL manpower. For a quick evaluate, I will split the tools in two types. 1. Main tool 2.Measurement tool, I will give it different MMR for tool operation. Measurement tool may have higher MMR ratio because measurement tool need a delicate DL to operate and monitor the progress or the process time is shorter need to load/unload frequently. The main tool have longer process time or automatically function to load/unload the products, so I will give it a lower MMR. We can get the tool number in FAB easily, and I can compute the DL needed quickly. For example, we have 100 sets main equipment and 20 sets measurement  equipment, the MMR is 4 for main tool and 2 for measurement tool. The DL amount is (100/4)+(20/2)= 25 + 10 = 35 in the same time. And this number multiplication tool average utilization and you will get a brief DL headcount number in one shift.

2.Time Study, It's IE's job, to measure each operation actions take how much time. In my company we split the action time to two types, first is index time, include move the product form previous stage to working stage, MES track in, track out, data recording etc, not operate the tool direct relative operation time. Any help or prepare to ready the machine work times. Second is operation time, it include load, unload, recipe setting, logsheet recording, monitor time shearing to each wafers etc.
We can combine these two types time to compute how much time each move needed. It's more accuracy than MMR model. But it take a lot of time to collect the data, and if any operation sequence change need to modify it. Thanks god' it's belong to IE. But MFG need to re-check the index time and operation time's detail, to prevent IE miss some key behaviors to under estimate the DL headcount.

These two way to get the full loading's TE headcount demand, and we will combine the tool loading's data. This data comes from MPS, we will use MPS to compute the average loading by day. Such as we have 100pcs wafer need to ship. MFG using the route and MPS demand, to generate each tool's move during the month. And dived 30 or 31 days, we will have ideally daily tool move demand. And get the demand dived tool daily capacity multiplication the tool available, and the tool average
loading are coming out.

Full loading's TE demand multiplication the tool average loading we will get the theoretical TE demand which you need.

It's a job need to corporate with IE, and convince your boos to buy in the number. This is the 1st stage to get the manpower, and I will show how to measure DL's capability next week.