Job Shop Inspection and Test - Where should we establish inspections? Why?

apestate

Quite Involved in Discussions
inspection and test in a job shop

Hello quality professionals

I am just getting started in a career of management in a small machine shop.

There is one thing about my ISO documentation that I haven't yet touched. Inspection and test status, or any provisions regarding the inspection and test part of our service.

I have never worked in a machine shop besides this one and I don't know how to approach it at all.

We do the following: Receive material, machine it on automatics, perform secondary operations, outsource for plating/grinding/heat treating, warehouse & ship.

My questions are: Where would you require inspection? How often? How would you identify parts that have been inspected? Can an machine operator's inspection or sign-off suffice to identify good parts, or for example, is the quality inspector's sign-off required to approve parts for the next operation?
 
R

Randy Stewart

atetsade said:
My questions are: Where would you require inspection? How often? How would you identify parts that have been inspected? Can an machine operator's inspection or sign-off suffice to identify good parts, or for example, is the quality inspector's sign-off required to approve parts for the next operation?

1) Incoming inspection of material, sample plan for machine operators, incoming inspection from outsource and final inspection based on a sample plan.

2) Identification would depend on packaging. You can identify bins, stamp boxes, etc. At the screw machine shop I worked at the operators had 2 bins good and bad parts.

3) Yes the operators signature can suffice. What does your control plan state? How is your process set up. You determine what states that a part can move on.
 
B

Bob_M

Randy Stewart said:
1) Incoming inspection of material, sample plan for machine operators, incoming inspection from outsource and final inspection based on a sample plan.

2) Identification would depend on packaging. You can identify bins, stamp boxes, etc. At the screw machine shop I worked at the operators had 2 bins good and bad parts.

3) Yes the operators signature can suffice. What does your control plan state? How is your process set up. You determine what states that a part can move on.

NUMBER ONE TIP: Keep it simple!
But be sure to inspect what NEEDS to be inspected.

Example:
Incoming - Measure/Verify Material Thickness, Width, Length, Hardness, etc BASED on the customer's, the product's and the company's requirements. If hardness was not a factor why would you want to measure it?

In-Process (1st op, 2nd op, last op...) Based on the individual operation and the part what do you need to verify? If the first step is to trim the part to 5in long, Measure the length. (If you are confident with your incoming inspeciton process, why would you need to re-measure thickness and width?) - Keep it simple - We're slowing working on this concept one part at a time (time permitting).

Make your inspection process fit you company and the parts. If you have a complex part, you may need a complex inspection. If you have a simple part, keep the inspection simple.
 

Cari Spears

Super Moderator
Leader
Super Moderator
Do you have a control plan for each job or "part family" in some type of format? We create a "Job Process Sheet" for each job. This is basically a router which is stapled to the manufacturing drawing that identifies the necessary manufacturing and inspection operations in the order that they shall occure.

At the completion of each operation there is a space for the machinist or inspector to sign and date. This router and print stay with the product throughout manufacturing, thus identifying the inspection and test status of the product. The next operation should not be performed if any of the manufacturing or inspection operations above it have not been initialed and dated.

As far as what and how frequently to inspect, we have to determine that for each job because each job is different from every other one. Some operations may be critical or complex, others routine. This must also be based on the skill level of the person performing the work. However, we do follow some general rules.

For example, if the product is to be heat treated there is always an in-process inspection operation prior to the heat treat operation. For us, heat treat is not usually the last operation. We ID, OD, Surface and Thread Grind to some tight tolerances and must usually finish after heat treat. It is alot less expensive to rework a piece before heat treat than after!

We do not require an inspector sign off at each operation as we are a shop full of skilled tradesman. We require a FPA at certain operations (done by an inspector) for 5 or more pieces. Otherwise, the machinists initial and date at their operations and the inspectors initial and date at their operations.
 

Mike S.

Happy to be Alive
Trusted Information Resource
atetsade said:
Hello quality professionals

I am just getting started in a career of management in a small machine shop.

There is one thing about my ISO documentation that I haven't yet touched. Inspection and test status, or any provisions regarding the inspection and test part of our service.

I have never worked in a machine shop besides this one and I don't know how to approach it at all.

We do the following: Receive material, machine it on automatics, perform secondary operations, outsource for plating/grinding/heat treating, warehouse & ship.

My questions are: Where would you require inspection? How often? How would you identify parts that have been inspected? Can an machine operator's inspection or sign-off suffice to identify good parts, or for example, is the quality inspector's sign-off required to approve parts for the next operation?
I'd work with the people that are there who have done this for awhile (I assume this shop has been open prior to your starting there) to determine where inspection steps should be and what the sampling plan(s) should be -- at least as a start.

The operator can certainly act as in-process and final inspector BUT it takes a certain culture for this to work well. I have seen it work very well and I have seen it fail miserably in the exact same industry. By fail miserably I mean lots of rejects intentionally passed on to the next step, and even to the customer, that never should have been passed. Operator self-inspection sounds great, and it can be, but in my experience more places THINK they have the culture for it to work than actually DO have the right culture. However you do it, you must be sure your shipped product is good or else you risk the business.
 
S

Shaun Daly

I couldnt make out if you were in the automotive industry or not, but a lot of tools are applicable to any manufacturing industry.

3 basic steps I would recommend are

1) Flowchart your manufacturing process.
2) Do a process FMEA to identify danger points.
3) Develop a Control Plan to enforce controls to eliminate the dangers.

There is lots of good info here on this site.

Attached is one format of a process flow.

As for inspection, you could do sample inspection on a batch from each machine, or if you are brave & the process is suitable run SPC on each machine & consider the lot passed if the process is very capable.

Or do away with inspection & Poka Yoke your way along if possible. I wish I could.........
 

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apestate

Quite Involved in Discussions
wow

thank you for all your replies. I wrote you all a nice letter about the whole thing but something happened to my computer.

maybe it's better if I just ask, is it necessary to have a control plan for every part? only the parts that put us at tier 3 to chrysler through this one company actually require any AIAG stuff. I only have to do a PPAP about once a month.

we have process travellers that state the operations performed on each bin of parts, the next process, and the routing. there is no provision for a required inspection on it, and I would redo the whole thing for the sake of clarity and content.

ideally and on parts not requiring any AIAG regulation, could the process traveller suffice? it seems easy to make a little check box next to each line item saying "inspection required." when we fill one of these travelers out for a new job, we'd checkmark the final inspection and any other points where inspection would be required. if no checks but final inspection, inspection would proceed according to the standard sample plan. if checkmarks, sign-off by the quality inspector according to her sample plan. does this seem ok?
 
S

Shaun Daly

atetsade said:
wow

maybe it's better if I just ask, is it necessary to have a control plan for every part? only the parts that put us at tier 3 to chrysler through this one company actually require any AIAG stuff. I only have to do a PPAP about once a month.

ideally and on parts not requiring any AIAG regulation, could the process traveller suffice? it seems easy to make a little check box next to each line item saying "inspection required." when we fill one of these travelers out for a new job, we'd checkmark the final inspection and any other points where inspection would be required. if no checks but final inspection, inspection would proceed according to the standard sample plan. if checkmarks, sign-off by the quality inspector according to her sample plan. does this seem ok?

You can get away with generic documents for family parts, especially if you have a large product range from "Pre-ISO" or TS. For proper planning for future products, shouldnt you have to prepare individual documents as per your customer SQA manual?

Another answer I have seen is that the Assessor agreed with the company to have individual documents ready for 25 old products by the time of the next audit.
 

Cari Spears

Super Moderator
Leader
Super Moderator
atetsade -

I guess when you said "job shop", I assumed you did not run production quantities. Quantity runs for us might be as many as 150-200 pcs. The traveler/router I described above works for us, it is our control plan, product identification, and status all in one. It may not work for you.

What exactly do you make? Are you automotive? I had worked in production car parts most of my adult life. The 6 years prior to my current job, it was prototype sheetmetal car parts. Now I've worked in the machine tool industry for the last 3 years. At each different type of shop everything was done differently.
 

apestate

Quite Involved in Discussions
in the year 2525

Cari & all viewers

I will give you some background.

I work in a 17 employee screw machine shop with 35 Brown & Sharpes and 5 multi-spindle New Britians. We have one Daewoo PUMA 10HC, and I hope to make its first parts on it this weekend. I busted the main breaker on it two days ago. Not to knock S. Korea quality, since I had to crank on it pretty hard.

Thank you all for your replies and help. This is amazing. It gives me great confidence to have a resource such as this forum. Amazing. I'm a full subscriber and will be for a while. I hope to become a contributor soon!

We produce parts in runs usually numbering 1000-5000 pieces. 75000 piece orders occasionally, and one job that makes a little 1/4" retainer cup in six seconds runs 8 hours a day continually.

Automotive (tractor, truck) are probably 3% of what we make. Seldom do we make a part that is not functional in some form, the exception being the rare knob or ubiquitous custom spacer job. Lots of odd fasteners and such, a part to fit an explosion-proof alarm box, very very diverse products.

I'm planning on setting up a control plan system and re-writing the job information each time we set up a job. We now have six different style brown & sharpes which each have different setups themselves. three different types of multi-spindle machines, and a CNC.

I'd like to see three different information sheets made well. Useful. The three machine types will be covered entirely, and these will be living documents that are filled out with recommendations at the end of the job by the people who ran the job. I will then confer with the expert and make the changes to the setup sheet.

As well as this, I would sincerely like to create an AIAG control plan and FMEA for each part.

I'm young. This company has been around for 25 years, and for the next 25 it is mine. I want to do the work and be a modern American company doing it the way it used to be done. TS-16949 could obstacle an opportunity at any time and I don't want to be ill-prepared.

What do I need to do to accomplish my documentation desires? I can do the job sheet and job engineering. I want to do something about the inspection control. We depend on our hard-*** Army Reservist inspector for all of quality control. She is good. I want to utilize her as a quality manager and I want to utilize the culture of accountability and excellence that is becoming powerful with our machinists.

We make a lot of parts and we have very few quality issues. Our company should continue depending on expertise, but provide ways to eliminate their busy human error.
 
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