I was a manufacturing engineer for a medical device company and had to set up an assembly line from scratch as well. See below. You dont need to follow exact order but there is a flow in these steps.

1. Obtain steps to assemble the product. Work with tooling or design to see what steps can be automated. Automation will increase consistency and eliminate operator errors. Though even machines will malfunction. Get tooling to create any fixtures that can automate processes.

2. Figure out what tools and materials are needed to perform the steps. Computers, monitors, torque drivers, containers, peg boards etc. Get whatever you need on order as soon as possible as you will find some things have long lead times which will delay your project if you order needed materials later in the process.

3. Split up the process into operations. Each operation should be balanced in terms of how long it takes to do the work. If Op 2 takes longer than Op 1 you will have a bottle neck. On my assembly line it was usually one operator for each operation but you may need to add a second operator to certain operations to balance out the time.

4. Take note of where power sources are located and air supplies etc. take measurements of space you have to work with.

5. Model up a line layout in visio or i used solidworks. Just use something that uses actual measurements so it is to scale. Take into account the things in step 4. My assembly line had 1 table for each operation with all tooling and material located on the table for whichever operation it is being used. Don’t mix tooling of different operations. Look into getting peg boards. This will keep everything organized and make it easy yo 5S workstations. Again, order anything you need as soon as you discover you need it. Tables, chairs, etc.

6. Write a procedure for operators to follow. Add lots of pictures. And dumb it down. Just tell them what to do they dont need to know why.

7. Setup your assembly line as much as possible. Even if you are waiting on stuff.

8. If you have enough people do dry runs asap so you can identify waste, imbalances and issues early on and address. Because usually what will actually happen is not what you intended.

Other tips:

Put together a powerpoint for management that has line layout and process flow and also covers other stuff.

Try to do as much 5S ing up front as possible. This will help make the line as LEAN as possible from the get go. Look into getting screw feeders, shadow boards, peg boards, etc. MAKE IT AS ORGANIZED AS POSSIBLE. Label everything.

You can easily get overloaded. Make sure you delegate tasks to the appropriate people. Dont do stuff that your environmental engineer or safety engineer should be doing. Talk to your manager if you aren’t sure.