October 6, 2017 | Author: KaranPahawa | Category: Printed Circuit Board, Industries, Technology, Nature
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Hal Case study, Industrial Engineering, ISYE, 3104, Manufactruring...


Pro-Coat at HAL, Inc.


1. Background It is March 2014. HAL, Inc. is a major manufacturer of computers and computer components. In their Lubbock, TX plant they make printed circuit boards (PCB's), which are used by other plants in the company in a variety of computer products. The Lubbock plant represents an $80 million investment and has approximately 450,000 square feet of manufacturing space. The basic manufacturing process involves the following major steps:          

Treater Process - woven fiberglass cloth is impregnated with epoxy to make ``prepreg'', the insulator used in multilayer printed circuit boards. Lamination - layers of copper and prepreg are pressed together to form cores (blank boards). Machining - the cores are trimmed to size. Circuitize - through a photographic exposing and subsequent etching process, circuitry is produced in the copper layers of the blanks, giving the cores ``personality'' (i.e., a unique product character). Optical Test and Repair - the circuitry is scanned optically for defects, which are repaired if not too severe. Drilling - Holes are drilled in the boards to connect circuitry on different planes. (Note - that circuitized boards may return to the Lamination process to build up multi-layer boards). Copper Plate - the boards are run through a copper plating bath, which deposits copper inside the holes, thereby connecting the circuits on different planes. Pro-Coat - a protective plastic coating is applied to the boards. Sizing - boards are cut to final size. In many cases, multiple cards are manufactured on the same board and are cut into individual cards at the sizing step. End-of-Line-Test - an electrical test of each board's functionality is performed.

The stated goal of the plant is to run 2800 boards per day, five days a week, with the plant running three shifts per day. Unfortunately, this goal can only be a rough one, since the different products have different manufacturing complexities. For instance, some products have many holes, causing them to move through Drilling very slowly. Others must make multiple trips through Lamination and Circuitize, which slows output. Therefore, the capacity of the plant and the identity of the ``bottleneck'' (i.e., the process that limits production) depends on the product mix being run. Despite these complexities, the plant manager, Salvatore Petitto, feels that an average throughput of 2800 boards per day is reasonable and is furious with his staff for their inability to meet this objective. He has begun calling a meeting of his line managers every day at 4:00 to discuss the details of why the target for that day was or was not met. Ken Czar, manager of the Pro-Coat process, has been ``beat up'' badly in recent 4:00 meetings. Despite the goal of 2800 boards per day, Pro-coat has been averaging around 1000 boards per day for the past several months. As a result, HAL has had to engage a vendor to perform the coating operation for the boards that they are not able to coat in-house. The cost of vendoring plus shipping is around $21 per board. Moreover, because the vendor is located in Michigan, this vendoring introduces a two-day delay because of shipping (up and back). Mr. Petitto has ordered Ken to take whatever measures are necessary to get Pro-coat's throughput up. 2. Consulting Experience In desperation, Ken contacted two consultants, Mr. Flash and Mr. Sparkle, from a major consulting firm to suggest ideas for improving Pro-Coat performance. Messrs. Flash and Sparkle made a review of the Pro-Coat process and drew up the graphical description shown in Figure 1. 1

 Wallace J. Hopp 1993




Coat 1


Coat 2

Touchup D&I






Manufacturing Inspect


Clean Room Figure 1: Layout of Pro-Coat Process

They observed the Pro-Coat process to involve the following steps: Boards arrive at Pro-Coat from Copper Plate in carts containing about 60 boards each (actually the number of boards per cart (job) varies between 40 and 72, depending on yield loss). Boards are loaded by an operator, one job at a time, onto an automatic loader, which feeds them into the Coater. The Coater is a conveyor that consists of three steps: Clean, which cleans the boards. Coat 1, which deposits a liquid plastic coating on one side of the board. Coat 2, which, after flipping the boards over, coats the other side. Boards are accumulated by an automatic unloader and an operator (who may be an Expose machine operator or another Clean Room worker) places them in carts in the Clean Room that contains the Expose machines. The boards are photographically exposed, one board at a time, on the expose machines. By using a special piece of film (called a diazo) these machines expose the boards to UV light, which makes the exposed plastic resistant to dissolving in the subsequent developing process. The purpose is to remove the plastic coating from areas of the board that must not have it (e.g., pads for mounting power supplies). Each expose machine requires two operators. An operator loads the boards into a loader which feeds them into the Develop bath.


As the boards emerge from Develop, they pass down a short conveyor. A D&I (for Develop and Inspect) Inspector must take each board off the conveyor and check it for defects and record the results on an adjacent table. He/she then replaces the board on the conveyor feeding the Bake oven. The boards travel through the Bake oven, which hardens the plastic coating and are accumulated on the other end by another unloader. A worker (generally someone from Manufacturing Inspect or the operator who loads the Coater) takes the carts of boards unloaded from Bake and moves them to another room containing Manufacturing Inspect (MI). There, Inspectors check each board with a magnifying glass for defects in the coating. Defective boards are marked and jobs containing defective boards are sent to the Touchup table (about 15% of boards). Jobs with no defects are sent out of Pro-Coat to Sizing. A worker (currently the Inspector between Develop and Bake) applies additional liquid coating to the defective boards and feeds them into the Bake oven for re-baking. At the end of Bake, these boards are rejoined with the others in their job and are sent out of Pro-Coat to Sizing. Flash and Sparkle also obtained the following information from Ken concerning the rates and behavior of the machines in Pro-Coat:

Machine Name 1 Clean Coat1 Coat2 3 Expose Develop Inspect Bake MI Touchup

Mean Process (Load) Time (min) 0.33 0.33 0.33 4 93 0.33 0.5 0.33 7 139 9 9.0

Std. Dev. Process Time (min) 2 0 0 0 5 67 0 0.5 0 8 64 0

MTTF (hr) 80 80 80 300 300 300 -

MTTR (hr) 4 4 4 10 3 3 -

Setup Time (min)



Notes: 1 30 minute cleaning per shift on Coater 2 Accumulator load time has standard deviation of 1 minute 3 30 minute warmup per shift 4 60 board job (time (minutes) = 1.55  job size)

74.82  job size )


60 board job (std dev (minutes)


Setup every other job 60 board job (time (minutes) = 2.33  job size)


68.3  job size )


60 board job (std dev (minutes) =


1 min/board requiring touchup (0.15  60 = 9)

It should be noted, however, that on the manual tasks, particularly Expose and MI, there is a substantial amount of variation between the rates of different operators. The data Ken collected was averaged over all operators. In addition to these rates, Ken estimated the following work stoppages: Work Stoppage

Duration (min)



Break Lunch Shift Change Meeting

20 40 1 10 120

2/shift 1/shift 1/shift 1/week

Notes: Does not include 25 minutes to start expose machines at beginning of shift.


With Ken's help, the consulting team also estimated the inventory buffers at each point in the line to be as follows: Buffer Location Before Expose After Expose At D&I Before MI Before Touchup

Capacity 1 5 4 40 15 10

Jobs or Boards Jobs Jobs Boards Jobs Jobs

Notes: 1 Does not include 2 jobs on accumulator (or jobs at expose machines). Finally, Ken pointed out to Messrs. Flash and Sparkle that because of various labor problems, Pro-Coat is not fully staffed at present. Specifically, the staffing levels were as follows: 1 loader (coater) 2 coater 1 loader/unloader (expose) 4 expose (2 on third shift) 1 send-ahead in expose 1 D&I inspector 3 MI 1 supervisor 1 maintenance 1 mover Ken said that additional people would cost $29 per hour (including benefits) and that because of training, vacations, etc., that every addition of a position would require an increase in ``on-board'' head count of 1.4. The consulting team made a careful review of the situation and submitted a report to Ken that contained the following recommendations: 

Current staffing levels are adequate. However, to motivate the workers to go faster, an illuminated sign displaying different slogans, such as “I love my job”' and “HAL Forever” should be installed in Pro-Coat.

An additional bake oven should be purchased for the purpose of re-baking the boards requiring touchup. This should be installed in close proximity to MI to minimize material handling.

HAL should look into slowing down the Coater, since it runs much faster than Expose. Current practice is to shut down the Coater for 3 hours whenever there are 5 jobs waiting in the Clean Room. If the speed of the Coater conveyor could be reduced, this would not be necessary.

This report came with a very elegant binding, full color graphics, and a very large bill.


3. Your Mission Ken was livid when he received the report (and bill) from Flash and Sparkle because he felt they had failed to back up any of their recommendations with numbers. He knew that if he presented these ideas without justification to Mr. Petitto, his job, his family security, indeed his very life, would be in danger. In desperation, he has called on you to provide him with a review of the situation. His primary concern is increasing throughput in order to reduce the need for outside vendoring. He wants ideas for improving output in both the short and long term. However, he is also concerned with costs. He is authorized to hire additional staff, and can get them quickly, but must be able to make a case that they will pay for themselves. He may also be able to requisition additional equipment, provided his argument is convincing to Mr. Petitto. Develop a set of recommendations for Ken. Justify your recommendations based on performance (throughput and WIP) and cost analysis. A report should be prepared using the following format: Title Page – Title, date, names of group members Executive Summary – Should contain a 2 to 3 paragraph summary of the important results found in the project. This summary should be self sufficient (i.e. a manager reading the summary would have a high level understanding of your work). Introduction Work Performed Conclusions Appendix – (if needed) graphs, data, detailed calculations, software, etc. Your target audience is Ken Czar. Therefore any mathematical details should only be referenced in the report and detailed in the appendix. The report should be turned the start of the class period on the date it is due (October 23, 2014) Grading will be based on the following factors. (65 points) Quality of solution (25 points)

Is the solution feasible and implementable? Are the arguments on the estimation of throughput and cycle time correct?

(25 points)

Are the calculations of costs for labor and additional capacity rational? Are the general costs expressions correct in mathematical format? The verbal description and mathematical cost statements are required.

(5 points)

Is the improved solution based on a good strategy and did it result a better plan in terms of cost/profit?

(10 points)

Does the solution demonstrate good judgment about the way a manufacturing line could be operated?

(35 points) Quality of presentation (5 points)

Is the executive summary brief, succinct, complete, and easily understood by senior management who would be in a hurry, but need to get the big picture quickly?

(10 points)

Is the body of the report well organized, well written, with good references to details in the appendices as needed? Does it explain the key issues? Have good transition? Contain a summary/conclusions/recommendations section?


(5 points)

Is the solution "justified" and explained to management in a way that can easily be approved and executed? (In the worst case (fewest points), the solution must be dug out from a bunch of spreadsheets with no explanation of what is where and how it was calculated and why it was done that way.)

(5 points)

Is the grammar, spelling, punctuation, typing, and overall presentation of professional quality?

(10 points)

Does the overall quality of the presentation measure up to “professional" level?


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