Does cycle time matter when running more than one machine?

[champshire]

Curious to the consensus here. If a person is running more than one op in a cell, does cycle time matter? For example, Op 10 takes one hour. Op 20 takes 1.5 hrs. Does it make sense to take any time out of OP 10?

My vote is yes, always try and make everything as fast as possible.

[CADCAM396]

As long as it is predictable, stable, repeatable process. sure speed it up. but makes no sense pushing it to the point you spend more time changing tools or chasing nominal.

[Zoffen]

NO cycle time does not matter.

Throughput is all that matters.

[Newbeeee™]

Definition of Cell...OP1 on a separate machine?
If yes, all focus is machine 2....

[CNCAppsJames]

Taking time out of OP01 doesn't lower your TAKT time so it's nothing more than mental masturbation "unless" you plan to use that extra/saved time for other things, then sure, it makes sense at that point.

Also worth considering, that time you spend tweaking and tuning, is this for a repeat job?

[champshire]

Great questions and points. Yes, two different machines doing two separate ops. I should have been more clear in my original post.

I agree that through put is the most important thing, but I am talking about taking the Op10 time from 1 hr to 34 mins. This is a real life example and something that I was able to accomplish.

These are repeat parts, and we do make 15ish parts that are the same. The process improvement on Op10 carries over to the other parts as well.

I wasn't sure if you guys would take in to account Machine run time, electric, way oil, etc. as something that would factor in as well. I understand something like 5 mins doesn't amount to a hill of beans, however. Where exactly is the point of diminishing returns?

My thinking was if Op 10 can be half the time of Op 20, buy a second Op 20 machine and double output.

[CNCAppsJames]

My thinking was if Op 10 can be half the time of Op 20, buy a second Op 20 machine and double output.

In that case... if total production is the goal and adding another machine into the cell is feasible then it's absolutely worth the time for an LTA project. 

[Newbeeee™]

My thinking was if Op 10 can be half the time of Op 20, buy a second Op 20 machine and double output.

This.
As twice the qty of parts are output, you're either selling double the qty = $$$$
Or
Then introduce 2x other similar parts into the cell, and run them with the extra machine capacity.
Either way = $$$$

[champshire]

So I guess my next question is did I waste my time taking time out, or would you have done it too? For the record, there isn't much if anything I can do to the OP 20 process, I have already taken as much as I can out of that.

[MIL-TFP-41]

I'm in the camp that cycle time does matter. Worst case in your example is you build up an inventory of OP10.
Say you are making 100 parts. After machine one is done with 100 pieces, machine 2 will have roughly 34 parts left to machine.

Now you can use machine 1 for 34 hours making a different part while machine 2 is finishing the order on OP20.

Ideally in your situation you would have 2 spindles on OP10, 3 on OP20, and the job would be done in 1/3 the time.

Side note...who ever came up with "OP10" for the first operation and "OP20" for the second was old AF. And I'm old. I believe was done in the days for when you forget an intermediate operation, then you can make "OP15". These days, it is pretty dated. Any software not capable of inserting an operation and renumbering is also old AF.

[Newbeeee™]

Now you can use machine 1 for 34 hours making a different part while machine 2 is finishing the order on OP20.

Or....
With decent quick changeover.... perhaps run OP20 finishing on Machine 1 for 30 hrs....

[CNCAppsJames]

I REFUSE to use OP10, OP20, OP30, etc...

On general principle alone. It's 01, 02, 03, etc... If I have more than 99 ops I need to re-examine my processes.

 

[Newbeeee™]

I REFUSE to use OP10, OP20, OP30, etc...

On general principle alone. It's 01, 02, 03, etc... If I have more than 99 ops I need to re-examine my processes.

But as MIL stated - look at all the temporary re-work OPs that can be added when you do use 10, 20, 30 etc....

[champshire]

That's how the sequence things here at work, that's what I'm used to. You are exactly right, we have op 35 and 37 for a reason....that reason is, oh shit we need to add this in.

Op 10 is lathe work and Op 20 is mill work btw. They would need to buy another vertical mill with a 4th axis, so it's not as easy as buying a new haas and slipping it in on the floor.

[CNCAppsJames]

So the extra numbers are for poor planning. 

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