Measure Phase Blog - Feb 2016

Measure Phase Blog - Feb 2016

Data Collection Process Map

The Measure Phase of DMAIC involves how the process data is gathered, determining what is important, studying the collected data and defining the baseline process capability. For the process X assembly line, there is a data collection method in place which allows the Production Administrator to obtain accurate Output and Reject figures for each stage in the process line, this can be used to obtain historical data to find baseline figures and to accurately keep track of future data. This data is gathered using the method shown on the process map to the right;

The gathered data was studied and the Output, Rejects, Yield and Sigma Level were calculated using the formula below; (Please Note the following, Number of Opportunities for defects = 8, Number of units 1,180,000 and the Sigma Level was obtained via conversion tables from the DPMO)

The information obtained from the data and the resulting calculations is shown in the table  to the right;

This table is extremely useful as it gives us clear information on each process and an overall indication of how the combined processes are performing. This will be of benefit when the Analyse phase begins.

A Pareto chart was generated for Process 3; this chart is useful as it gives us a clear  indication of why the parts have been rejected and will be a useful metric in the Analyse phase.

The tools that were used in the Measure Phase have allowed an accurate baseline for the project to be calculated, the data collection method shown in the above process map will be used throughout the duration of this project. As a result of the Measure Phase the 'Project Statement' and the 'Objective Statement' have been updated to the following;

'Project Statement; The product X process has an average reject rate from Jan - Dec 2015 of 4,945 parts p/m. This corresponds to DPMO = 6285. Which indicates a Sigma Level of  3.9 sigma'

'Objective Statement; Reduce the DPMO to <3140 within 6 months, to do this  scrap must be reduced by 50%. This is around 2,472 rejects p/m. If a DPMO of 3140 is achieved, this will allow a Sigma Level of 4.2 sigma to be achieved'

Define Phase - Feb 2016

Project Statement - The production process has an average reject of 4,000 parts p/m from Jan - Dec 2015. This corresponds to a DPMO = 6275 and a Sigma level of 3.9 sigma. 

Objective Statement - Reduce the DPMO to <3125 within 6 months, to do this scrap must be reduced by 50% to around 2,000 rejects p/m. If a DPMO of 3125 is achieved, this will allow a sigma level of 4.2 to be achieved.

Team members were chosen the week beginning 18th of January 2016. I held a team meeting on the 22nd of January, this meeting followed the following procedure;

•  A brief introduction on the six sigma process was given for the benefit of the team members who had no previous experience of the process.
• Critical to Quality (CTQ) and the Voice of the Customer (VOC) where defined and the 'Project Statement' and the 'Objective Statement' were defined.
• The whole process was mapped, with a focus on the three manual assembly processes that will be looked at.
• A brainstorming session took place for these three manual assembly processes.
• The processes were written in the centre of a flip-chart. Each team member anonymously wrote down process improvement suggestions / reasons for high rejects on post-it pads. The post-it's were stuck around the central process. The suggestions were reviewed and combined if similar.
• An action plan was formed.

Brainstorm of process 2

VOC - The customer wants a good quality product that is fit for its intended purpose. For product X this is a clean and solid weld in both the 'filter and plug' and the 'septum swage' weld process, with no leaks from either weld.

CTQ - Septum Weld - A good weld will not leak, it will have a thin rim of flash around the septum, it will sit level in product x, there will be no holes and there should not be excessive flash. Filter and Plug weld - The plug will be placed the correct way, filter will be positioned correctly, no holes in the filter and no cracks in the plug.

Brainstorm of process 3

The CTQ, VOC and the process mapping allowed the operators to see the full scope of the product they are making, and the importance of it when in use by the customer. The brainstorming allowed them to express their opinions anonymously and so, truthfully. Overall the tools used in the define phase where extremely useful in making the problem clear to all involved, getting primary feedback from the process line and outlining possible process improvement ideas.

We aim to achieve the lower reject rate, higher productivity and lower downtime by a combination of the following;

• Better welding horn cleaning products
• Modifications to; welding horn, product opening nest, welding nest, sensory equipment and the inspection table.
• Train operators to change the pierce pin, tune sensor and to adjust the welding parameters as required
• Have a stock of spare parts.
• Define a reject
• Reduce paperwork
• Introduce a camera inspection system.

An extract from the process flow, showing the 3 assembly processes that will be looked at