Return On Investment: Progressive Die Metal Stamping Application

By: Process Technologies Group, Inc.
Topics: Metal Stamping Die Protection, Defect Detection, Continuous Improvement, IMPAX, IMPAX TSS

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.

Overview and Present Situation

The focus of this RFA is to utilize technology to increase quality, to 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
• 2,738 production hours
• $1,314,794 in sales
• Client 081 is the customer
• 13 SNR's (Supplier Notification Reports) from client
• 13 8-D investigations at this facility (Plant 151)
• 100 RDF's (Reject Disposition Forms) internal reject

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, 2) IMPAX data collection method, 3) Operational trial with results and 4) System cost.

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 the voltage profile of each of the four channels is 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 ram position. If the press varies outside the tolerance levels, IMPAX top-stops 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 IMPAX 2000 supports data collection from multiple IMPAX 2000 to a host personal computer using IMPAX TSS software through a network. With each process fault, downtime reason codes are entered. Also, the reaction time to start the fault investigation and total down time are recorded. In addition, current part number on each press, time for completion, press stop or test, and actual production speed of each press is available at the host personal computer. The IMPAX TSS reports eliminate manual data collection, making the system a true real-time management tool.
3. The operational 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 set up with four sensors. One tool maker and one press associate were involved during the trial. A fault log was established for each detected process fault or force error and the associated 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 units. A high-level audit was performed on each lot of parts and there were zero press-related defects. In addition, by using the IMPAX TSS error log 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. Also, the IMPAX units give immediate feedback 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.
   
   
4. System Cost:
   
   

   4 IMPAX 2000 Monitors

   $34,380

   1 IMPAX TSS Network

   $2,995

   3 Additional Connections

   $1,500

   1 OPTO 22 Comm Card

   $500

   * Service Technicians

   $4,000

   Total System Cost

   $43,375

* The $4,000.00 charge for Service Technicians is an "all inclusive" fee that will provide Plant 151 with installation support. Two individuals will spend two days at Plant 151 providing training, technical assistance during installation and network setup. The fee does not cover sensor installation. Sensor installation will be handled through internal Tool Room accounts.

Benefits

The benefits of installing the IMPAX process monitors will be achieved in four areas: 1) The dollar value of non-value activities due to bent and distorted parts, 2) Immediate identification of potential tool breakage and other process failures, 3) Management of press downtime and 4) Opportunities to increase process efficiencies.

1. Dollar value of non-value activities due to bent and distorted parts.
   • Replacement of bent parts accounted by RDF (Reject Disposition Form) and SNR (Supplier Notification Report) 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 part between Client 081 and Plant 151.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, 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 the Plant 151 Quality Manager. These estimates were provided in an internal 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 of 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 have been avoided by the IMPAX process monitors, that quantity was used.
     
     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 savings
   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. Immediate identification of potential tool breakage and other process failures provides two main benefits:
   
   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 toolmaker or press operator receives feedback if their action was appropriate. This eliminates wasting time while waiting to see if the problem returns, and provides increased confidence that the die and press are protected from damage.
3. Management of press downtime is an arduous task and self-reporting is often ineffective. By utilizing the internal clock in the IMPAX TSS unit in combination with the IMPAX TSS Network this task can be automated. The clock records reaction time of press operator after press stops. The IMPAX TSS also records total downtime by reason code. The downtime reason codes then can be used for continues process improvement. With accurate recorded reaction time and downtime, 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.

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