Six Sigma Project - Control Phase

Six Sigma Project - Control Phase
Assembly and test capacity expansion.

Control Phase

The purpose of the control phase is to maintain the gains that have been achieved by standardizing work method and processes. The control process should make plans to preserve the lessons learned from the earlier phases to enhance continual improvement.

Six Sigma 6S manufacturing services procedure.

A manufacturing services procedure and checklist was developed to maintain a 6S culture. This will ensure the maintenance of a clean safe assembly and test environment which will inevitably lead to a reduction in non conformances. 

Clean room check list

To maintain the cleanliness and housekeeping in the assembly clean room a daily, weekly and monthly sign off sheet (Fig 20) was developed. The checks are carried out by the supervisor and the operators to ensure a good culture is developed.

Fig 20: Excerpt from the clean room cleanliness control sign off sheet. Click image to enlarge

Borescope Inspection.

To control the cleanliness of the manifolds and to verify that the de-burring process is completed correctly a new Borescope inspection camera (See Fig 21) was purchased. All manifold bores are inspected by the quality control inspection department and signed off before assembly.

Fig 21: Borescope for manifold bore inspection, Click image to enlarge.

 

Automatic washer for manifolds

After the de-burring process all manifolds are cleaned in a new automatic washer. (Fig 22) This removes all debris from the de-burring process which is also verified by QC inspection using the Borescope. Only items that have been passed and signed off by inspection can be issued to assembly, controlled by the SAP ERP system.

Fig 22: Automatic manifold washer,center. With 2 Manifolds. Click image to enlarge

Improvement to job routings

The routing have been revised to reflect the savings realized by the improvements made in the improve phase. This has resulted in a reduction in assembly and test time of 7 hours which equates to an annual saving of €102,000. The new routings will now be the new standard work method going forward.

Fig 23: Old and new routing layouts. Click image to enlarge.

Increase in production output.

All the improvements done to date have significantly reduced production time and waste. The introduction of the new flow rig to test bay C while maintaining test bay A and the automation of the test processes will ensure that production will increase from 12 units per month to 18 units per month, an increase of 50%. 

Training and control of the new calibration flow rig.

A training program has been developed by the manufacturer of the new calibration flow rig. The training will be carried out on an ongoing basis by the R+D engineering group who developed the software. All personnel who receive training will have their training records updated accordingly. Only trained personnel will have the authority to log on to the control HMI interface and operate the flow rig. A preventative maintenance (PM) schedule has been drawn up for the upkeep and servicing of the new rig.

Next Steps

The team have now completed the all five phases of the DMAIC process. (Define, Measure, Analyze, Improve and Control), This does not mean by any means that all work is complete, the control phase is a continuing process that can be further developed and modified to make continual improvement going forward.

Six Sigma Project - Improve Phase

Six Sigma Project - Improve Phase
Assembly and test capacity expansion.

Improve Phase

The purpose of the improve phase is to carry out improvements and work towards moving from the current state value stream to the desired future state value stream. This blog entry will show how the team carried out the improvements.

"Just do it" items

The "just do it items" identified in the measure and analyze phases have been actioned and purchase orders have been placed for new equipment.

Action plan CSVSM to FSVSM

An action plan was put in place to bring the current state value stream map in line with the future state value stream map, as follows.

• Devise method of de-burring manifolds.
• Purchase new assembly fixtures.
• Create new clean room layout to accommodate dual assembly.
• Introduce preventative maintenance schedule for flow rig filtration change.
• Design and purchase new flow rig.
• Create new test bay layout to house new flow rig, use Test Bay C.
• Automation of Flow Rig.
• Modify assembly and test work order routings in line with FSVSM.

De-burring of manifolds

We were having problems during the assembly procedure with burrs on the small diameter internal bores on the manifolds. We procured a simple de-burring tool which fits in a standard hand drill. (See Fig: 15)

Fig 15: New manifold de-burring attachment, Click image to enlarge.

Purchase new assembly fixtures
Two new assembly fixtures were purchased and are now in place.

Improvements in layout for assembly clean room

The current layout in the assembly clean room is cramped and allows only enough space for one operator to assemble one product at a time. The new layout drawing below Fig: 16 shows the new layout which makes better use of the space by incorporating a new corner bench, This allows adequate space for two products to be assembled simultaneously.

Fig 16: New assembly clean room layout drawing, Click image to enlarge.

Improvements in layout of Test Bay C

The team made a decision to leave the present calibration flow test rig at Test Bay A and to install the new Automated Flow Rig at Test bay C. Test bay C is not being used due to a serious drop in demand for the product line it supported. The below drawing Fig 17 shows how the new flow rig is being incorporated. We will use Test Bay C for most testing and support it with the old manual unit at test Bay A, (e.g. For rework, Surge in demand, Etc.)

Fig 17: New Layout drawing for Test Bay C test cell showing the location of the new flow rig.
Click image to enlarge.

Automation of flow rig

A new software application was developed by the R+D group using the LABVIEW programming environment. This will fully automate the calibration process for Product A. The new system will mean that we will no longer have to rely on the specialized skills of a few operators and we will have an automated system that anyone can use with a small amount of training. (See GUI below Fig 18)

Fig 18: New automated flow rig graphical user interface, Click image to enlarge

Future State Spaghetti Diagram
A new future state spaghetti diagram, (Fig:19), was generated using the new work breakdown structure and future state value steam map created during the analyze phase. It can be clearly seen that the waste of movement has been reduced significantly, by comparing the new spaghetti diagram to the original current state spaghetti diagram.

Fig19: Future State spaghetti diagram, Click image to enlarge.

Next Steps

The team have now completed the first four phases of the DMAIC process. (Define, Measure, Analyze, Improve and Control), The team will now move forward to the control phase.