Embracing Tools for Continuous Improvement | MillerWelds

Embracing Tools for Continuous Improvement

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Kaizen can be applied to many areas of welding. It requires the involvement of everyone, from top management to the level of the welder. It also requires the presence of in-process controls for continuous improvement. This article discusses the basics of Kaizen and keys to successful implementation - as well as an example of how one structural steel application improved its flux cored welding process.

Abstract

One of the major differences between Japanese and Western management styles is the time frames used to measure success. Japanese management has a long-term perspective, while Western managers tend to look for quick results. When introducing the Kaizen approach in the workplace, however, top management must be committed and aware that it will take time to produce results. Otherwise, any effort to introduce Kaizen to the company will fade before it ever flourishes. Changing corporate culture is really the only way to nurture Kaizen.

Kaizen can be applied to many areas of welding. It requires the involvement of everyone, from top management to the level of the welder. It also requires the presence of in-process controls for continuous improvement. The ISO 3834 welding quality standard provides a good working tool to this end.  Part 6 of this standard explains well the need for process control and emphasizes the involvement of top management in welding activities.

What is Kaizen?

Kaizen is a Japanese term that means continuous improvement, taken from words “Kai,” which means continuous and “Zen,” which means improvement. Kaizen is not a single event, but rather a continuous heartbeat in an organization, embraced at all levels and applied to all aspects of the business. Kaizen is a philosophy of working!

In the Kaizen philosophy, any change or suggestion that contributes to the following goals is given priority for implementation:

  • Making the job easier

  • Removing nuisance and drudgery from the job

  • Making the job safer

  • Making the job more productive

  • Improving product quality

  • Saving time and reducing cost

Standards and Measuring System

In any business, management creates standards that employees must follow to perform their jobs. Companies that embrace Kaizen generally require business managers to maintain and improve standards. It is imperative that an objective means of measuring performance is available to allow everyone to know, at all times, if the standard is being met (or exceeded). Clearly, instituting a method to measure and monitor performance for continuous improvement is a necessary criterion for the process to work. Lasting improvement is achieved only when people work to higher standards. For this reason, maintenance and improvement of standards go hand in hand.

In the welding business, for example, estimating standards in a company may be based on technical data, such as deposition rates or historical data, where actual hours can be compared with the standard’s welding hours to know if the contract is making or losing money. If an accurate, highly visible cost-control system is not in place as the job progresses, experience has shown that, in most cases, the job will result in cost overruns, delays in delivery and loss of profits.

Those of us who deal with managing welding man-hour overruns find that, in most cases, the labour-hour statistics come in too late in the life of a contract to take any corrective measures. In some other instances, standard welding hours may be regularly revised upwards to absorb past inefficiencies, eventually forcing the cost of the product out of the market in a competitive environment.


Kaizen Sees Problems as Opportunities for Improvement


The value of improvement is obvious. Whenever process improvements are made, these improvements eventually lead to better quality and productivity. Improvement is, therefore, a process. The process starts with recognition of a need that becomes apparent when you recognize a problem. Kaizen puts an emphasis on problem-awareness and will lead you to identify a problem.

The real issue is that the people who create the problem are often not directly inconvenienced by it, and often adopt a laissez-faire attitude towards it. They tend to take the inconvenience for granted. In day-to-day management situations, the first instinct is to hide or ignore the problem, rather than to correct it. This happens because a problem is an unwelcome event in a non-Kaizen organization. By nature, nobody wants to be accused of having created a problem. However, if you think positive, you can turn every problem into a valuable opportunity for improvement. Simply put, when you identify a problem, you must solve it. Through continuous monitoring, you can consistently surpass previously set standards, taking the process to a new, higher standard of performance.

For the welder, if his weld has too much reinforcement or an undercut, generous use of grinding is never questioned!! Excessive grinding in a job shop is taken for granted. This is a very expensive inconvenience. The proper corrective measure would be to avoid the discrepancy in the first place, through adequate skill training immediately when it first occurs! This is where responsible monitoring and supervision can pay off.

Kaizen Requires a Long-term Commitment

Kaizen managers are people oriented and understand that process improvement takes time. The results of Kaizen are not often immediately visible. Although implementation of Kaizen does not call for large investments, it does call for a great deal of continuous effort and commitment. Often, only common sense and simple techniques are needed for improvement. However, once changes have been integrated in a company’s day-to-day working, the improvements are permanent.

Non-Kaizen organizations, on the other hand, are often obsessed with innovation. These organizations hope to reap benefits before doing the homework of improving their operating processes. Innovation also requires investment in technology and often can be radical or disruptive. Middle managers in such organizations can usually obtain support for innovative projects because such projects offer a return on investment that is hard to resist on a short-term time horizon. On the contrary, when a lead hand wants to make a small change in the way his workers perform a task, obtaining management support can be difficult because the improvement in the process does not immediately show a large return on investment. If profit is the only measure of performance, then management will be reluctant to implement improvements that risk hurting short-term profits, even if the long-term benefits of such change are obvious!

In a welding shop, for example, if a foreman requests installation of a small jib-crane for making the assembly of welded parts easier, often his appeal will be ignored, the equipment considered unnecessary! However, management may look favourably to invest in an expensive machining centre or a robot that may remain idle for long periods of time.

Kaizen, Innovation and Business Growth


In a slow-growth economy, Kaizen is often a better solution than relying on innovation for growth. When Kaizen is first introduced, many companies see productivity increase by 30% to 100%, all without any major capital investments. Kaizen helps lower costs and lets management become more attentive to customer needs, as it creates an environment that takes customer requirements into account. Kaizen does not replace innovation. In an ideal situation, innovation takes off after Kaizen efforts have been exhausted, and Kaizen begins again as soon as innovation is implemented. Kaizen and innovation together make progress.

The example of the Toyota Motor Corporation is perhaps the most revealing success story of this decade. Toyota pioneered the application of Kaizen and Lean concepts to automotive manufacturing. Its vehicles are competitively priced with unsurpassed quality. Once management had exhausted its Kaizen efforts, innovation took off to create a new standard: the hybrid vehicle. This shows the power of Kaizen!

Kaizen Applied to Welding Operations

It is difficult to know where to start to implement Kaizen in welding, as welding is a complex process. Moreover, in-process controls are required to ensure high quality in the weld. In other words, the finished weld might look good, showing no non-conformance, but could still contain a defect that can be revealed only through destructive testing or additional ultrasonic or radiographic testing.

To properly control welding, many in-process parameters must be verified. For example, in just semi-automatic welding processes (GMAW, FCAW and MCAW, for example), there are more than 27 parameters, including choice of welding process, choice of weld joint, plate thickness, type of base and filler materials, weld size, weld pass and layer sequence, wire diameter, wire-feed speed, welding speed, welding current and voltage, electrical polarity, shielding-gas type, gas-flow rate, welding technique and progression, preheat, post-heat, inter-pass temperature, weld backing, back gouging, electrode stick-out, deposition rate, heat input, and distortion.

To deal with this multitude of decisions, welders should have adequate training prior to performing production and, in most cases, should have access to a well-documented welding procedure that would help in choosing the correct parameters. For semiautomatic welding, what are the most important parameters, affecting quality and productivity? Kaizen should be applied to the following three parameters as a start:

  • Wire-feed speed

  • Welding technique

  • Welding speed

To illustrate how Kaizen can be applied to welding, let us review the results of a case study. Thirteen experienced welders, working for a structural-steel bridge-manufacturing contractor, were asked to weld 12-inch-long, 5/16” fillet welds, using 1/16”-diameter FCAW wire in the 2F position. The welders were asked to execute the test plates at their own workstations, to reproduce the welding parameters used for production. These welders were experienced and were assumed to be efficient in their work. 

Table 1 shows the measured data and the results of the testing.

Table 1: Case history with Kaizen for FCAW structural 5/16” horizontal 2F fillet welds. After 12 months of monitoring, average welding speed increased to 14 ipm., wire-feed speed to 350 ipm, over-welding reduced to 15% and all welds passed. The welding technique was changed to a pull technique.

Team

Sample number

Required size (inches)

Wire-feed speed  (in/min)

Technique Push/pull

Welding speed (in/ min)

% over welding

Visual evaluation Acc./Rej.

Penetration evaluation Acc./Rej.

Global evaluation Acc./Rej.

Night

1

5/16

235

45º push 15º-30º

11.8

-20

Acc.

Acc.

Rej.

Night

2

5/16

212

40º push 0º-5º

7.9

10

Acc.

Acc.

Acc.

Night

3

5/16

236

40º push 0º-5º

9.5

68

Acc.

Rej.

Rej.

Night

4

5/16

220

40º push 15º

10.6

40

Acc.

Rej.

Rej.

Night

5

5/16

211

40º push 0º

10.9

-10

Acc.

Acc.

Rej.

Day

6

5/16

222

40º push 0º-10º

10.1

40

Acc.

Rej.

Rej.

Day

7

5/16

259

35º push 5º

9.2

44

Acc.

Rej.

Rej.

Day

8

5/16

302

40º-45º push 5º

9.6

68

Acc.

Rej.

Rej.

Day

9

5/16

219

45º push 15º

7.6

20

Rej.

Rej.

Rej.

Day

10

5/16

241

45º push 0º-5º

7.2

44

Acc.

Rej.

Rej.

Day

11

5/16

200

45º-50º push 10º

10.0

-10

Acc.

Acc.

Rej.

Day

12

5/16

210

45º push 15º

7.2

44

Acc.

Rej.

Rej.

Day

13

5/16

210

45º push 25º

6.4

44

Acc.

Rej.

Rej.

     

Average

 

Average

Average

Accept

Reject

Reject

1/16"-diameter FCAW wire, 100% CO2

229

 

8.8

29.4%

12

9

12
 

  • Average wire-feed speeds were measured at 229 ipm. An average wire-feed speed of 350 ipm was attained after 12 months of monitoring.

  • All 13 welders were using the wrong welding technique. Several years ago, the welders had been transferred from a GMAW welding facility (where a push technique is recommended) to a structural-steel FCAW facility (where a pull technique produces best results). The quality results were disastrous!  Twelve out of 13 welders failed to produce welds to the required specification, and 9 of 13 failed to produce acceptable penetrations. Changing the technique and increasing the wire-feed speed solved the penetration problems.

  • The observed travel speed was measured at 8.8 inches per minute. This value is almost half of the optimized travel speed to deposit 5/16” fillets using the flux-cored arc welding process. The average welding speed was increased to 14 ipm after 12 months of monitoring.

Role of Senior Management for Kaizen as Applied to Welding

At the structural-steel fabrication facility discussed above, there were many more welders than the 13 tested. Following the audit findings, several recommendations were implemented. The training of welders was specifically designed to give them feedback on the quality of the macros. This was achieved over a period of 12 months. Initially there were many non-believers. Over time, both quality and productivity improved. The president of the company was the most visible and eloquent supporter of this process; he had set the stage and created the environment for change. There were no more bridge components returning for repair. 

A similar Kaizen approach was followed with an agricultural manufacturer. Immediately after the audit, the CEO was ecstatic. He ordered standardization of the weld-monitoring operation.  Over the last eight years, the average wire-feed speed for GMAW with 0.035”-diameter wire has increased from 420 ipm to 600 ipm. Over this time period, the welder population has also steadily increased from 90 to 150 welders, as the company now exports its products all over the world!

The ISO 3834 welding quality standard is interesting. It describes many important process-control parameters to ensure that welding remains under control.  The newly introduced part 6 of the standard provides a useful guide for its application and shows several diagrams, one of which involves top management. This diagram has been reproduced in Figure 1.

Conclusion

Kaizen is an interesting process to apply to welding. It produces, in most cases, spectacular results. It is not disruptive; however, it takes a commitment of the whole organization, including the president or CEO.  The two examples cited here are a small sample of over 100 welding-performance appraisals carried out in Canada over the last 10-year period. The good news is that it works! It is truly an exciting journey in human engineering.

Viwek Vaidya is Senior Expert at Air Liquide (http://www.ca.airliquide.com [Canada] or http://www.us.airliquide.com [United States]) and Andy McCartney is Manager of Welding Services at Omniweld Integrated Solutions (http://www.solutionomniweld.ca).

For more information, contact:


AIR LIQUIDE INDUSTRIAL
2700 Post Oak Boulevard
Houston, Texas 77056-8229
Phone (800)820-2522
Fax (800) 715-4799
e-mail: us.info@airliquide.com
www.us.airliquide.com

This story originally appeared in the Canadian Welding Association Journal - International Institute of Welding Special Edition (August 2006, www.cwa-acs.org). It is reprinted with permission.
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