Best process question

[romad]

What is the best(quickest) way to assemble something with multiple steps of equal effort/time?

a) Complete all required steps for one unit at a time.

or b) complete one step at a time for all units

[stomachmonkey]

How many units and how many individual steps per unit, how complicated, how many parts?

If just a few I don't think it matters.

If 10 or more then I would build at least one or two completing all required steps just to make sure I understood all the steps then I'd go to completing one step at a time for the balance.

You want to avoid a misstep that makes you have to backtrack on multiple units.

[Noney]

I believe it's a generally accepted practice to complete an entire unit before moving on to the next one. This prevents you from applying the same mistake to multiple units and then having a bunch of completed, yet incorrect, units. No matter how careful you are, there's always room for errors and the hope is that if you begin making an error as you complete units, you'll catch it in time and not trash your entire assembly run.

[cashflyer]

Originally Posted by romad

What is the best(quickest) way to assemble something with multiple steps of equal effort/time?

a) Complete all required steps for one unit at a time.

or b) complete one step at a time for all units

You'll need to take it up with the shop steward.

[Rich Lambert]

Originally Posted by Noney

I believe it's a generally accepted practice to complete an entire unit before moving on to the next one. This prevents you from applying the same mistake to multiple units and then having a bunch of completed, yet incorrect, units. No matter how careful you are, there's always room for errors and the hope is that if you begin making an error as you complete units, you'll catch it in time and not trash your entire assembly run.

What he said...one piece flow.

[Porsche-O-Phile]

Subcontract it and add 5% markup.

[IROC]

Completing one step at a time for all units would also require you to have all of your inventory there at the beginning (not practical or cost effective) where completing the entire units one step at a time allows "just in time" inventory management and continuous process improvement. Sorry, had to through in two buzz words.

[wdfifteen]

A factor to consider is how long it takes to prepare for each step. If it takes a while to get the tools, get in position, put tools away, clean up, etc. for each step you might be better off getting set up, doing all of that step, clean up, put tools away, etc, and then moving on to the next step.

[widebody911]

Originally Posted by wdfifteen

A factor to consider is how long it takes to prepare for each step. If it takes a while to get the tools, get in position, put tools away, clean up, etc. for each step you might be better off getting set up, doing all of that step, clean up, put tools away, etc, and then moving on to the next step.

This. I make various repro parts, and it's just me, so I'll make batches of each of the components separately, and then assemble a final unit all at once. I'll do a few complete units, then paint them all at once.

[Z-man]

Originally Posted by IROC

Completing one step at a time for all units would also require you to have all of your inventory there at the beginning (not practical or cost effective) where completing the entire units one step at a time allows "just in time" inventory management and continuous process improvement. Sorry, had to through in two buzz words.

This. Inventory management, especially in a just-in-time system is critical.

Addtionally, by assembling multiple units at a time, one can introduce concurrent operations to the mix, with careful coordination of the entire process. This should allow a quicker completion of the total number of units being built, provided there is sufficient workforce to support concurrent processing.

Geez - I think my MBA studies are finally starting to pay off!

-Z-man.