Due to the high demand of deliveries for Energy Australia earlier this year, a decision was made to run a Kaizen event on the assembly of Power Drives.
As with the Ergon cell the focus was on the one piece flow cell concept, the sequencing of operations, reduction in cycle time and the identification and reduction of waste.
A team was chosen who have had considerable experience with Power Drive design, manufacture and assembly and also Kaizen experience.
The team recorded:
Total area used was = 80sq/mtrs.
Walking distances for retrieval of components was 650 metres per Power drive.
4 operators were required by ST Point scheduling software.
The times of each process were recorded and the cycle time for one Power Drive was calculated as 260 minutes although some versions are up to 297 minutes.
Working environment was cluttered, with packing crates as assembly benches.
Components were difficult to access or strewn in various locations.
Batching of assemblies was common practice.
Assemblies in various stages of completion.
Limited access for forklift into adjacent racking.
Recorded times were transferred to bar charts by hand.
Operator sequencing was determined by transferring those times to a series of combination work charts.
Some operations were combined for ease of operator sequencing
3 versions of operator sequencing reduced the cycle time from 260 minutes to 135 minutes.
A Spaghetti chart was created to determine the movements staff required to assemble. Each Power Drive required approx 650 meters of walking to retrieve components from Stores, yard area and Factory 1 at 27 Walker St for nameplate engraving. This equated to 1.62 klms per day.
Version 4 of Operator Sequencing
Further reductions were expected when the walking distances were reduced with the new cell layout. The team used the combination work chart and spaghetti chart To reduce cycle time Decide correct sequence of standard work Synchronise sub assembly and main assembly operations Reduce operator movement
The team decided on a U shaped counterclockwise cell layout
Ergonomically positioned part racks in easy reach of operators
Modified jigs and fixtures
Dedicated drilling machines for each operation to reduce jig set up times
Lift trolleys for ease of access and movement of the assembly around the cell
A white board was introduced to allow the management walk around and operators to track orders to ensure progress was on time.
Dedicated drills to eliminate jig set up time
Dedicated fastener and tool trolleys
New benches for component storage and ease of access.
Adjustable trolleys for ease of operators to manipulate components from storage locations.
Result of the new cell design and counterclockwise one piece flow layout.
Results allowed the cell operators to keep up with the required TAKT time for Energy Australia deliveries.
The more significant results were:
Required area reduction of 24% Cycle time reduction of 48% Crew size reduction of 25% and will hopefully soon reach 50% reduction Inventory and WIP remained the same as the scheduling process still operates to purchase components Productivity increase of 66%.
Greg - Slide 13 To do
There are still further improvements to be investigated such as:
Shaft and stop design to remove the welding process Chain cut to length by subcontractor Din rail cutter which has already been implemented New crane to eliminate sharing with Ergon Supply and install of the electrical loom which is our main constraint or our ‘Drum beat’ Hand over to continuous improvement team The cell operators have already listed various other improvements on their whiteboard.
PD cell Kaizen event presentation
Assembly of Power Drive Units
Greg Williams and 7 other team members who
shall remain nameless for this version of the
presentation. Those chosen had considerable
experience with the existing power drive
manufacturing and assembly process and had
some exposure to a previous Kaizen event
The team recorded:
• Area = 80sq/m
• Working environment was a small area in the aisle
between assembly benches and racking.
• Limited access for forklift into racking when assembling
• Walking distances 650 metres per PD x 2.5 PD a day =
1.62km per day
• No of operators = 4 required by ST point scheduling
• Cycle time = 260min
Packing crates as benches,
cubicles stored on floor
Components difficult to access
Components strewn in various
Batching of assemblies
Recorded times were transferred to bar charts
Version 3 - New two operator sequencing
Version 3 with a further 30 minute reduction in cycle time. Now 135 minutes.
Further reductions were expected by reduced walking times with new cell layout
Parts retrieval spaghetti chart
650 mtrs walked for each
Power Drive assembled equated to
1.62klms per day
Version 4 - New two operator sequencing
NOTE: Further reductions expected by reduced walking times with new cell layout.
Recording of new times still required to show 15 minute reduction in cycle time.
The target of 4 Power Drives a day was achieved.
• The team used a combination work chart to:
– Reduce cycle time
– Decide the correct sequence of standard work
– Synchronise sub assembly and main assembly operations
• Decide on U shaped counterclockwise cell layout
• Right sized part racks and buckets within easy reach
• Modified jigs and fixtures
• Dedicated pedestal and bench drills for eliminating jig setup times
• Lift trolleys for one piece flow assembly providing easier access
and manipulation of assemblies
• Fastener and tool trolleys
• Crane for ease of lifting into cabinet and crates
White board was installed for operators and
management walk around to track progress
Dedicated drills to
jig setup times
positioned for ease of
Adjustable trolley heights reduced operator
movement when accessing heavy parts
Result of New Cell Design
Before After Improvement
Area 80sq/m 61sq/m 24% reduction
Cycle time 260min 135min 48% reduction
2 req normal
4 req for EA
3 in training
Target of 2
25% reduction in ST
planned crew size
Target is 50% crew size
WIP = = None
Inventory = = None
PDs per week
PDs per week
• Further gains are anticipated through investigation of
– Shaft and stop design to remove welding process
– Chain cut to length by subcontractor
– Breather gauze and foam cut by subcontractor
– Din rail cutter which has been implemented already
– Wire handle cap retaining chain made outside
– Crane required – Sharing with Ergon cell at present
– Supply and install of the wiring loom. This is essentially our
– Hand over to continuous improvement team/cell operators
– Cell operators have already listed various other
improvements on their whiteboard