TRIZ Paper:


Application of TRIZ to Manufacturing Phase -- Case Study of Eliminating Defects in Printer Assembly Process --
Yosuke Koga ( Panasonic Communications Co.)
Presented at The Third Japan TRIZ Symposium, Held at TOSHIBA Kenshu Center, Yokohama, on Aug. 30 - Sept. 1, 2007
[Posted on Dec. 23, 2007]  Under the permission by the Author.   

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Editor's Note (Toru Nakagawa, Dec. 22, 2007)

The paper posted here was originally presented last August at The Third TRIZ Symposium in Japan held at TOSHIBA Kenshu Center, Yokohama.  The paper was presented in a plenary session on the first day afternoon, and was evaluated as one of the most significant results (besides the Keynote Lectures) of the Symposium by many participants.  I have reviewed this presentation in my 'Personal Report of The Third TRIZ Symosium in Japan, 2007'   , by citing 11 slides, and wrote my impression at the end as:

*** This case study is most impressive in many points: achieving to solve a big problem in a short time by generating many solution ideas, deriving effective measures, executing many measures at once, etc. In the photos of the slides we can see that people seriously got involved in this project and had experienced the change in their mind. This is also an excellent case study for stepping up the TQC style activities into much elaborated one with the philosophy of TRIZ. 

--- This case study is worthy of written down in a full document in Japanese and in English and published/posted widely. --

I am very happy to be able to post this presentation in full length both in English and in Japanese in this Web site "TRIZ Home Page in Japan".  We should appreciate the Author, Mr. Yosuke Koga, and Panasonic Communications Co., Ltd. for their excellent TRIZ activities and for their openess in presenting and publishing their results vividly.  [Note: The Slides shown in this page are the versions revised recently by the Author.]

This page contains the followings:

[1] Abstract (by the Author)

[2]  Nakagawa's introduction: Excerpt of my 'Personal Report of Japan TRIZ Symosium 2007'  

[3] Presentation slides in PDF (41 slides, 4 slides/page, 2.3 MB) )   

[4] Links to Japanese page

 
Top of this page Abstract Nakagawa's introduction Slides in PDF (2.3 MB) Japanese Slides PDF Japan TRIZ Symposium 2007 (Nakagawa Personal Rept.)   Japanese page

 


[1] Abstract

Application of TRIZ to Manufacturing Phase
- Case Study of eliminating Defects in Printer Assembly Process -

Yosuke Koga (Panasonic Communications Co., Japan)

Panasonic Communications Co. Ltd. has been promoting to use scientific techniques in the whole process of product development and manufacturing; they include (1) the QFD technique in the product planning stage, (2) the TRIZ method for solving technical problems in the product development and design stage, and (3) the Quality Engineering (i.e., the Taguchi Method) for setting and validating the design parameters in the design stage. We have been using these to develop new products which satisfy the requirements of Q(quality), C(cost), and D(delivery date) and to deliver merchandise of customer satisfaction.

The present paper reports a further extension of the TRIZ application fields, especially in the manufacturing process. This work was achieved together with the people in the manufacturing plant. More specifically, the assembly process of the printers has been improved by a project using various techniques; the problem of a kind of defects was left till recently and was finally solved by the application of TRIZ. The case study will be reported to some detail.

 


[2] Introduction & Review of the Presentation (Toru Nakagawa (OGU), Nov. 14, 2007)

Excerpt from Nakagawa's 'Personal Report of Japan TRIZ Symposium 2007' (posted on Nov. 18, 2007).  [Note (Dec. 22, 2007): The Slides shown in this page are the versions revised recently by the Author.]

Yosuke Koga (Panasonic Communications Co.) [5] gave an excellent presentation of his case study with the title of "Application of TRIZ to Manufacturing Phase -- Case Study of Eliminating Defects in Printer Assembly Process --".  Panasonic Communications Co. (PCC) is most active in applying TRIZ company-wide and to a wide range of problems. PCC has already established several tens of TRIZ specialists in its 'Development Process Innovation Group', who are working actively to support various divisions in the company (and also other companies in the Matsushita Group).  The present case was carried out in spring, 2005, at their Saga Plant in the manufacturing process of a color laser printer.  Here I am going to quote 11 slides to reproduce this valuable case study. 

The following slide shows the position of this paper in the aspect of deploying TRIZ to further down-stream stages of manufacturing in the PCC.  The Author tried to use TRIZ, in this case study, to the Production stage, or speaking more directory, to improve a factory.

The plant was manufacturing a new color laser printer, but had a lot of trouble at first.  Using various methods the troubles were reduced, but still there remained two big problems in the printer cartridge plant (on the 3rd floor) and in the main body assembly plant (on the 1st floor).  The TRIZ team assisted first to solve the problem caused in the printer cartridge plant and succeeded in solving it.  Then the manager of the 1st floor requested the TRIZ team to support solving the bigger problem in the main body assembly plant.  The problem was the high defect rate of the printer mostly due to appearing spots and stripes on the printed papers. 

The following slide shows the overview of the approach for 'Applying TRIZ to Improve Factory', actually used in solving the '1st Floor Problem', i.e. the second and bigger problem mentioned above.  The process will be described below step by step along with illustrations and photos.

The first step is to state the problem, or the undesirable results, and to understand the current situations and to find causes of the problem.  In such a step, TRIZ groups in PCC usually apply the 'Naze-Naze Tenkai', or the procedure to ask 'Why?' and 'Why?' several times for going down to 'root causes'.  However, the Author did not use the method in this case, because such 'Why?' questions tend to sound blaming somebody or the members themselves and tend to close the members' hearts.  The Author held a study meeting of all the section members to explain the trouble situations, and then made the Brain Writing Session with the participation of all the section members.  The members are requested to write down their ideas freely with the question 'Why the defects occur?'.  All the section members participated in this Brain Writing and wrote down 638 ideas all together in 30 minutes (see the bottom right photo in the slide below).   

Then all these ideas are analyzed by the TRIZ team by using the Key Graph Method (shown in the slide below) to find out the relationships among the items mentioned by the members and reveal the hidden main structure of the causes.  With this analysis, it is found that the main cause of the defects is the dust, and that the reform of members' mind is indispensable.  The defects are also analyzed with scientific methods, such as observing the dusts with microscopes. 

Then all the Brain Writing comments on the causes and on ideas for improvement are analyzed to form groups.  The framework of 4M (i.e., Man (or Work), Machine, Method, and Material) + 1 (Environment) is used. The results of grouping are shown in the slide below.

Then the ideas are further classified in the form of a tree structure of factors as shown in the following slide. 

Then the ideas written by the factory members are built up into a system of solution ideas keeping the framework of the tree structure.  As shown in the left part of the slide, all those ideas are classified in the classes of readiness of practice; they are: possible (or ready to apply immediately); with condition (or ready to apply with some preparation or after solving some minor problems); difficult (or need much preparation or difficult to apply in spite of being desirable).  Numbers of such ideas in these categories are shown in the right-most column of the slide.  Thus a huge number of solution ideas are obtained, even though in the column of 'Measures idea' only one of them is written in each box.  (You will see some of such solution examples in the following slides.)

Then a large number of solutions were implemented into applicable measures and were actually executed.  The next slide shows some examples of measures in relation to work (or working style/behavior of people).  (1) The cleaning time is increased from once a day to three times a day while the places to be cleaned are divided in time and the rotation of people is posted on a board explicitly.  (2) In the shoes closet at the clean room entrance, the places to put shoes are specified, i.e. the shoes for for the clean room are to be placed at the upper box while those for outside at the lower box.  (3) Discipline is enforced to put hair inside the working cap.  All these measures were executed at the same time.

After executing such a large number of measures, the defect rates of the products were reduced much, but not zero yet.  Thus the problems and their solutions were checked again with the eyes of TRIZ.  For example, as shown in the following slide, even though the dirt and dusts were collected with a vacuum cleaner, some dirt's are still remained because we cannot see them well.  Then with the aid of 'Prediction' module of a TRIZ software tool, the 'Black light' (i.e., the UV light source which cannot be seen with human eyes but can excite some dirt's to emit fluorescent visible light) was introduced to see the dirt and dust more clearly (See the bottom right of the slide). These activities to find solutions were navigated by the TRIZ specialist team.

Eventually, the factory have executed 549 measures in response to the 638 ideas.  The results of executing all these measures are clear in the following graph of the defect rates plotted monthly.  The defect rates dropped dramatically since the project started in April 2005, and finally became zero in August in relation to the dust problem.  These results are evaluated to be nearly one million dollar savings per year. 

The influence of this project on people is clearly seen in the photos shown below.

The Author summarizes the key points of their 'TRIZ Way of Improving Factory' as follows [I tried here the English translation of their Japanese slide]:

1.  Construction of the root-cause tree without a 'Why? Why? ...' session, and use of TRIZ
        ## Participation by all the members in the Factory section, and
             activities reflecting all the ideas coming from individual members

2.  Guiding people with the TRIZ philosophy, generating 500+ ideas in a short time, and
       managing to execute a large number of measures to solve the problem
          ## management does not care the validation of individual measures

3.  Integrated use of multiple methods to derive tasks and to generate solutions
        ## People have experienced a sure achievement, and thus obtained strong self-confidence

4.  Collaboration of TRIZ experts with all the factory people,
        where TRIZ experts guide (with the TRIZ philosophy) the factory people to generate ideas
        for improving their own work and work place. 

*** This case study is most impressive in many points: achieving to solve a big problem in a short time by generating many solution ideas, deriving effective measures, executing many measures at once, etc.  In the photos of the slides we can see that people seriously got involved in this project and had experienced the change in their mind.  This is also an excellent case study for stepping up the TQC style activities into much elaborated one with the philosophy of TRIZ. 

--- This case study is worthy of written down in a full document in Japanese and in English and published/posted widely.

 


[3] Presentation Slides

Presentation Slides (in English)   (PDF, 2.3 MB, 41 slides, 4 slides/page)  Click Here. 

 


[4] Links to the Japanese Pages

Japanese page

Pesentation Slides in Japanese   (PDF, 2.7 MB, 41 slides, 4 slides/page)

 

 
Top of this page Abstract Nakagawa's introduction Slides in PDF (2.3 MB) Japanese Slides PDF Japan TRIZ Symposium 2007 (Nakagawa Personal Rept.)   Japanese page

 

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Last updated on Dec. 23,  2007.     Access point:  Editor: nakagawa@utc.osaka-gu.ac.jp