Cost calculation 3

[var10]

Hi

I am trying to calculate the cost of using a clinch nut press machine. Quick background - we have bought a new clinch press machine and I am trying to show how much it would cost the company to use this machine to press nuts on. What are the factors that I need to consider, if I want to calculate the price involved in pressing one nut?

Compare this to using rivet guns and how much that will cost us? Might be a bit silly, first time trying to calculate costs for my design. Go easy!

Its a pemserter series 4 inserter.

Any help is very much appreciated.

Thanks,

V.

 

[tygerdawg]

I would approach it as a side-by-side comparison of the two methods.
Account for these expenses over a sufficiently long production time to get throughput rate (not cycle time) and cost per action for realistic comparison:
1. Machine setup time.
2. Workpiece load time.
3. Part insertion time (if manual).
4. Actuation (cycle) time.
5. Workpiece unload time.
6. Workpiece inspection time.
7. Worker break times & lunch times.
8. Cost of consumables: rivets vs inserts, air, electricity (if possible to quantify).
9. Cost of operations (maintenance, workcell re-arrangement, etc).
10. Cost of delivering workpieces to / from machine.
11. Cost of dunnage & removal of dunnage.
12. Cost of "change in quality" between one method & the other, if quantifiable.
13. Oh, yeah, add in an efficiency rate, too.
14. Anticipated reject rate (or other quality index) and rework time, or cost of scrap.
15. Economic issues could figure into this also: cost of equipment, finance charges, payback calculations.

All times are with labor rates.

You could also take it even further by performing a "weighted comparison matrix" ("Pugh Matrix") to rank & score aspects of each method that are important to your particular factory. Doing this has helped me provide context about my conclusions when making my pitch to managers.


TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[Cockroach]

No, you approach the problem egronomically.

Have a technician press on the piece repeatably for eight hours a day, five days a week. Correlate acceptance to rejection critia; what can go wrong? Define some level of acceptability between mating pieces and break out operator induced rejections.

Then do the same with your secondary system. Repeat the process using your riviting system.

So you compare acceptance/rejection by statistical inference based on a test statistic like 99% efficiency using a probablisitic curve such as the Student T for small sample size, or the Gaussian curve should the population tested be large. Given your rejects, what does that cost the company in terms of lost product and lost man time? What about maintence on the machines on the floor. What about cost of supply, rivets that are an expense to the company verses nuts that are made inhouse or local commercial availability and supply.

Summarize your findings in a report and have the process laid out in detail for your peers. Summarize your findings on the front sheet, everyone is busy and wants the executive summary first. If they have an issue, they can dive into the details or your support. Ask them for comment and response in a definite time period or make a presentation and summarize your findings.

That is what I would expect for any of my engineers in the company. An educated and methodical approach to problem solving. It's not just a nut being pressed on to a shaft, it's about selling your abilities to maintain the safety, welfare of the employees and show your employer that you have a vested interest in the financial affairs of the company.

Regards,
Cockroach

 

[var10]

Really appreciate your comments. This is exactly what I was looking for!! I can obtain almost all data except don't know how to calculate the costs on how much air and electricity used.

Thanks again guys!!

 

[berkshire]

VAR 10,
You should be able to get the air and electricity costs from your maintenance department if you have one.
I believe the series 4 is pneumatic only, with air logic, so you should not have to worry about electricity.
Also get several people to use the machine and check their output. Very often a person who seems slow , but works steady will have a higher output at the end of the day, than a faster worker who takes cigarette breaks, or frequent bathroom breaks.
B.E.

You are judged not by what you know, but by what you can do.