When Mr. Sinha, VP - Quality left the factory that day evening at around 07:00 pm, everything was normal in the factory with no major quality issues. He had given instructions to his night shift managers to take care of the inspection and control points in the night shift. Mr. Sinha had been working for the last 15 years in the Organization. The Company manufactures automotive parts which involve rubber to metal bonding. As in any organization, there were always small tussles between the Production head Mr. Durai and Mr. Sinha, whenever parts are rejected. Mr. Sinha used to blame the Production supervisors for not educating/supervising the operators to follow the standard work practices for most of the problems. Mr. Durai used to blame the inspectors for not doing proper in-process checks and for not approving the setup approval properly. Mr. Durai’s principle was that the role of Quality department was only to take care of the Quality and if anything went wrong with the product, it was the Quality department that was responsible. Mr. Durai joined the company much before Mr. Sinha and was of the opinion that he knew the processes and product much better. On that day, Mr. Durai also left the factory around 08:00 pm, after giving instructions to his Production managers.

The next day morning, as soon as Mr. Sinha, entered the factory, there was a big commotion. The reason: the batch of parts which was produced in the night shift was rejected due to a chronic defect called "Bonding loose" and the shipment could not be done to the customer. Mr. Durai also had reached the factory by then. Soon, there were altercations and finger pointing as to the reasons that had lead to the defect. Production Manager of the Mould shop Mr. Sinnarkar, a cool headed guy was also there and he asked his Supervisor Mr. Himat whether the problem happened due to any operator error involved in the moulding process. "Kya sab, I was there throughout supervising the production. The operator Mr. Singh was very sincere. Ye defect, kabi kabi atha hai, it is not due to operator mistake". This was the reply from Himat. In between, Ms. Poonam, the process engineer entered the shop and she on her part told that this had happened due to the parts not being shot blasted before moulding. She was of the opinion that this could not occur due to the Moulding process. Mr. Durai called the shot blasting and Painting supervisor and asked him when the parts were shot blasted. The supervisor replied that these were done the previous day in the morning shift and he was sure that all parts were shot blasted and the defect could not have happened due to parts not being shot blasted. He also gave his opinion that this defect could have happened due to improper chemical application on the metal part before moulding.

To put an end to all this atmospheric analysis going on on the shop floor, Mr. Sinha said that, "we have to study the problem systematically and resolve it through Six Sigma techniques". He said he was forming a cross functional team immediately with Mr. Sinnarkar representing the production function, Harish his Quality manager, Poonam from process engineering and also Mr. Singh the operator from Mould Shop. Mr Sinha said that he would oversee the work of this group and he would guide systematically on how to identify the root causes for this problem and make sure that the problem was solved permanently. Mr. Durai reluctantly agreed to this saying that " Is mei systematically karne ka kya hai. The reasons are already known. You have to tighten the inspection after setup with your people and ensure that periodic shop floor rounds are done by your inspectors. The problem will be resolved. Ye tho nahi ho rahi hai. That is the reason for the problem". Finally that day, after wasting around 2 hours on discussions, it was resolved that the team would work to reduce the defect of "Rubber to metal bonding loose" systematically by taking it as a Six sigma project. The team leader would be Sinha, with the following members in the team: a) Harish b) Poonam c) Sinnarkar d) Singh. It was also decided that the first meeting would take place the same day in the afternoon and the agenda would be to first clearly DEFINE the problem, for them to proceed further. Sinha told Harish to provide all the relevant rejection data on the problem.

02:30 pm in the afternoon, the team had already assembled to define the problem clearly so that they could continue with their next phase of investigation. Sinha was leading the meeting and result of the meeting was tabulated as follows:-

Process sequence of manufacturing the part:

Blanking ⇒ Sand blasting ⇒ Degreasing ⇒ Pre-heating ⇒ Chemical application ⇒

The team also decided that that the entire investigation of the root cause would be completed within 15 days and all the actions and controls should be in place within 30 days. Now, it was the turn of the team to do brainstorming and list down the likely causes for the problem. Sinha moderated the entire session. First Sinha asked Sinnarkar, the production guy, on what he thought was the possible causes for the bonding loose. Sinnarkar, falling back on his experience, opined that the following things could have lead to the problem.

• Time delay between the Chemical dipping and moulding
• Gasket handling with bare hands
• Time delay between the Chemical dipping and moulding
• Chemical not applied properly in certain holes

Chemical not applied properly in certain holes Harish, the Quality Manager, interjecting, said that there was no chance that the temperature could vary in the moulding process, hence it could not be the reason. Sinnarkar irritated at this, told Harish that he did not know much about the process as he hardly visited the shop floor to sees the process. A heated exchange ensued between Sinnarkar and Harish. Sinha interrupted to point out that they were only in the process of brainstorming to identify the possible reasons for the problem and nobody was pinpointing any thing at that moment using their knowledge was very sure that the problem could happen only due to one cause which was Parts not being shot blasted or Shot blasting miss. She also added that there was no mistake proofing to ensure that the parts are shot blasted. Being a process expert, she said that the moulding process could not have created this problem. Sinha laughed at her stubbornness. Now it is was the turn of operator Singh. He said that according to him, he had seen that whenever he reworked the part for short fill, he found that this problem of loose bonding occurred in that piece. He says "Bahut bar maine supervisor ko bola, but he has not taken any action on reducing short fill rejection". He also says that "I have also told many times about this to Quality inspectors also, and they turn a deaf ear to this, as nobody wants to listen to me”. Sinha said that this time it would be taken up and a proper study would be done on this. Finally it was the turn of Harish, the Quality Manager. He said that according to him, there was one more likely reason which he had seen himself many times. After usage, the Chemical became milky, and he had seen that sometimes, when the parts were chemically coated before moulding, loose bonding happened. He also said, that he was not sure whether this was the only reason or not. Finally, the team decided on the following Suspected Sources of Variations (SSV's) or likely causes of Poor bonding problem.

• Sand blasting missing on partial area of one or more holes
• Application of Milky chemical on the part
• Reworked gasket due to Short fill
• Moulding process
• Time delay between chemical dipping and moulding
• Gasket handling with bare hands
• Chemical not applied in certain holes

It was 04:30 pm and the group had come up with a clear problem definition with the likely causes. Sinha told the group that now they had to move to the MEASURE AND ANALYSE phase, were he would be guiding the group on the application of the appropriate Shainin techniques to pinpoint the reasons from the suspected ones listed. To start with, he told Sinnarkar, that he had to monitor the rejection cavity wise for two shifts and come up with the data of Cavity wise rejection %. He told the team that the name of this technique was Concentration chart and the purpose was to find out whether the defects occurred randomly or was concentrated in certain cavities. He told Singh to record the rejection cavity wise in his working shift. They agree on the data collection and they decide to meet on Thursday at 10:30 am sharp. Sinha was happy that he had been able to accomplish the task of completing the problem definition and also initiating the data collection. He also went to Durai and told him about the work they have done. Durai, who was a little apprehensive initially, was now pretty sure that the problem could be resolved since the team has gone about working in a systematic way.