Return On Investment: Stamping Application

By: Process Technologies Group, Inc.
Topics: Stamping Die Protection, Defect Detection, Increased Run Times, IMPAX

ROI analysis for using IMPAX monitors to advance quality and reduce cost in a stamping application

This is an actual Return-on-investment study prepared by a customer, for IMPAX monitors. Names and some details have been removed.

Present Situation

The focus of this project is to utilize technology to advanced quality, monitor, and control the stamping processes and to reduce non value cost for Plant 151. Initially, this equipment will be installed on Plant 151's four Minster P-2 stamping presses that have a production/quality profile outlined as follows:

28 part numbers
24,639,000 annual volume
8.65% of total volume for Plant 151, cost center 6
2,738 production hours
$1,314,794 in sales
13 SNR's (Supplier Notification Report) from customer
13 8-D investigations
100 RDF's (Reject Disposition Form) internal rejects

Proposed Situation

The proposed situation is to install an IMPAX 2000 Process Monitor on each of the four Minster presses. Each IMPAX 2000 will be networked to a personal computer for data collection.

The following descriptions outline 1) IMPAX 2000 function and operation, and 2) Operational trial with results.

1. IMPAX 2000 is a computer-based Process Monitor tool. Piezo sensors are installed into recessed pockets located in the top die shoe under the punch holders and sealed with epoxy. Crystals in the sensors produce a voltage signal when excited by pressure or audio force. This voltage signal is conditioned by IMPAX and each of the four channel inputs voltage signal profile learned by the computer. The computer assigns an upper and lower tolerance to the conditioned voltage signal based on a timing window generated by the press. In addition, the IMPAX 2000 is capable of trend recognition, allowing the computer software to continuously adjust the tolerance settings thereby reducing nuisance stops. If the press is stopped by IMPAX, the operator receives a fault message with information including input location, high or low reading, and force reading for improving fault troubleshooting.
2. The operations trial for IMPAX was conducted over a period of six weeks, with three production setups and a total of 554,000 press cycles. Initially, tool number 200-808-0 and 200-607 were each setup with four sensors. One tool maker and one press associate were involved during the trial. A fault log was established for each IMPAX fault or force error and the associates recorded channel number (1-4), counter number, high/low reading, three channel force readings, and the reason for fault if problems were identified.

   There were many positive results during the trial period for the IMPAX unit. A high level audit was performed on each lot of parts and there were zero press related defects. In addition, by using the log fault data, a Pareto chart was made for continuous improvement. Finally, the most significant outcome of the trial is immediate identification of pulled slugs that were not detected by the load monitors (using strain links) or the existing die protection system. Also, the IMPAX unit gives immediate feed back for the resolution of other identified process problems including lack of leader pin grease, loose leader pins and weak springs that are listed on the Pareto chart as action items.

Benefits

The benefits of installing the IMPAX Process Monitors will be achieved from four areas, 1) The dollar value of non-value activities of bent and distorted parts, 2) Immediate identification of potential tool breakage well before any catastrophes occur or quality is jeopardized, 3) Management of press downtime, and 4) Opportunities to increase process efficiencies.

1. Dollar value of non-value activities from bent and distorted parts.
   • Replacement of bent parts accounted by RDF and SNR reports in the last 12 months. A factor of 75% was used in an effort not to overstate the equipment's performance.
     RDF 78,884 + SNR 111,827 = 190,710 pieces
     $54.36 average value per 1000
     (190,710) ($54.36) = $10,367
     75% reduction equals $7,775 savings
   • Shipping rejected component parts from Plant 151 to customer and returning. A factor of 75% was used in an effort not to overstate the equipment's performance.
     815,757 returned SNR
     34.18 lbs per 1000 average weight
     815.757 / 34.18 =27,882 lbs
     $116 per 1000 lbs shipping cost
     (27.882 lbs) ($116) = $3,234
     Round trip total $6,468
     75% reduction equals $4,851 savings
   • Cost avoidance of die damage is based on empirical information from the Engineering Manager, Manufacturing Engineer, Tool Designer, and Tool Room Supervisor. Based on the IMPAX trials, the system will be 100% effective in eliminating broken strippers and punch sets.
     Broken Stripper
     14 pulled slugs during 554,000 piece IMPAX trial
     554,000 pieced / 14 pulled slugs = 1 slug every 40,000 cycles
     24,639,000 annual volume
     24,639,000 annual volume / 40,000 = 609 opportunities for die damage
     Stripper breakage factor: 1.5% of pulled slug
     (609) (1.5%) = 9 broken strippers
     Replaced broken stripper requires 40 hours at $20 hours = $800 per stripper
     ($800) (9) = $7,2000 savings
     
     Broken punch and die set
     $150 average punch and die set from 6605 account
     Punch and die set breakage factor: 10% of pulled slug
     (609) (10%) = 61 broken punch and die set
     (61) ($150) = $9,150 savings
   • Cost of Quality as detailed by Plant 151 Quality Manager. These estimates were provided in a memo and are based on averages.
     SNR
     13 total
     SNR value $100
     75% reduction is SNR = 10
     ($100) (10) = $1,000 reduction in non-value activities
     
     8-D
     13 total
     8-D value $350
     75% reduction in 8-D = 10
     ($350) (10) = $3,500 reduction in non-value activities
     
     RDF
     100 total
     RDF value $50
     75% reduction in RDG =75
     ($50) (75) = $3,750 reduction in non-value activities
   • Sorting or reject component part. The quantity of pieces sorted was cataloged by all documented SNR's and RDF's during the most recent 12 month period. If the sorting activities could of been avoided by the IMPAX Process Monitors, that quantity was used. The criteria for sorting is outlined in the "In-process Visual Audit Sampling Plan" and "Final Audit Sampling Plan".
     1,425,917 pieces
     1,500 parts hour sorting rate
     1,425,917 parts / 1,500 parts hours = 950 hours
     (950 hours) ($12 hours) = $9,506
     75% reduction equals $7,129
     
   
   Summary of dollar value from non-value activities from bent and distorted parts.
   
   

   Replacement of bent parts

   $7,775.00

   Shipping

   $4,851.00

   Die Damage

   $16,350.00

   Cost of Quality

   $8,250.00

   Sorting

   $7,129.00

   Total Benefit

   $44,355.00

   
   
   
2. There are two main benefits from immediate identification of potential tool breakage and other process failures.
   First, too often the source of pulled slugs cannot be identified. In a 20-station progressive die, if a slug is pulled in station two, the press must cycle 19 times before the pulled slug can be identified on the part. After 19 press cycles, the slug is so badly distorted, identifying its location is difficult. In many occurrences after the first slug is pulled, several more follow causing tool damage. Therefore, the benefit is instantaneous recognition of pulled slug, not contingent on visual inspection after forming and coining of final part.
   Second, with immediate identification, the tool maker or press operator receives feed back if their action was appropriate. This eliminates wasting time while waiting to see if the problem returns and increased confidence die and press are protected from damage.
3. Managing press downtime is an arduous task and self reporting is often ineffective. By utilizing the two internal clocks in the IMPAX 2000 this task can be automated. The first clock records reaction time of the press operator after the press stops. The second clock records total down time by reason code. The reason codes then can be used for continuous process improvement. With accuracies recorded reaction time and down times, continuous improvement activities will improve press efficiencies.
4. There will be many opportunities to increase process efficiencies by continuous press operation during lunch and to reduce manning requirement. These opportunities will be explored after the equipment is installed.

Alternatives

There are no other known technologies that offer this level of process control, instantaneous recognition, and error recording. The only alternatives are to continue with the current methods that are producing modest results.

Submitted by:
[Name Removed]
Applications Engineer
Plant #151

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