Project Storyboard: Herding Cats Using Lean Six Sigma – How to Plan for and Manage the Chaos of Parallel Processes
Home Âŧ Case Study Âŧ Project Storyboard: Herding Cats Using Lean Six Sigma – How to Plan for and Manage the Chaos of Parallel Processes
GoLeanSixSigma.com Green Belt John Pettit’s project is a great example of how effective Lean Six Sigma can be in helping all sizes and types of organizations. John volunteered his time and experience to help a local nonprofit organization remove waste in their process thereby allowing them to increase the overall capacity of the services they provide which therefore yield additional revenues to help the people they serve. Congratulations to John in clearly demonstrating his knowledge of the Lean Six Sigma methodology and tools and using his expertise to help others.
â Craig Tickel, GoLeanSixSigma.com Master Black Belt Coach
Project Charter - Problem Statement
LH ships between 1,200 and 1,400 Stuff Sack ship sets per month. The true cycle time is not known. Monthly production needs to hit 3,000 by the end of August, and 6,000 some time early 2018. Management does not have the information necessary to assess if these production targets and timeline can be met.
Project Charter - Goal Statement
To determine the production capacity needed to generate part cycle times below 180 seconds (takt time @ 3,000) by Aug. 31st, and 90 seconds (takt time @ 6,000) by a date TBD.
Project Charter - Scope
- Start: Work order by part or ship set
- End: Work order parts packed, palletized and ready to transport to Shipping Dept.
- In: Part work order, materials, process steps and WIP.
- Out: Ship sets of (1) PJ Flaps Assy. SS96-032, (2) PJ Patch Web/Buckle Assy. SS96-031, (1) Bottom Panel SS96-028, (1) Top Strap SS96-033, (1) Body Panel SS96-027
Project Charter - Business Case & Benefits
- Not meeting these production targets will jeopardize a substantial long term revenue stream for both companies.
Project Charter - Timeline
Phase | Planned | Actual |
Define | 05/27/2017 | 06/15/2017 |
Measure | Â 06/02/2017 | 07/01/2017 |
Analyze | 06/09/2017 | 07/10/2017 |
Improve | 06/16/2017 | 07/14/2017 |
Control | 06/20/2017 | 07/15/2017 |
Project Charter - Team Memebers
Position | Person | Time Commitment |
Team Lead | John Pettit | 75% |
Sponsor | Brent Weichers | 10% |
Team Member | Stuff Sack Area Lead | 20% |
Team Member | Job Coach | 20% |
Team Member | Shop Floor Rep | 20% |
Operational Definitions - Key Terms (Specific to The Lighthouse for the Blind)
- LH: The Lighthouse for the Blind
- Stuff Sack: Stuff Sack is a water proof sack used to compress and keep dry a sleeping bag used in the field. It consists of 5 components: 1) Patch Web/Buckle Assembly (Assy.), 2) Bottom Panel, 3) Body Panel Assy., 4) Top Strap Assy., and 5) PJ Flap Assy
- Primary Contractor: Organization that subcontracted LH to produce component parts of the Stuff Sack, that they in turn, assemble into a Stuff Sack
- Ship Set: A set consists of the five component parts of a Stuff Sack shipped at the same time as a set
- DoD: Department of Defense
- Support Staff: LH personnel providing low skill services that are not assigned to Stuff Sack, but available as needed
Operational Definitions - Key Terms
- Takt Time is the rate (rhythm) at which a finished product needs to be completed in order to meet customer demand
- Cycle Time (CT) is the actual time it takes to complete a process from start to finish to produce one unit (one cycle of operation). An employees cycle time must meet takt time(with an appropriate buffer of safety time)
- Process is the series of steps required to produce a product
- WIP refers to raw materials, labor and overhead costs incurred for products that are at various stages of the production process
- Ship Set is a complete set of all parts required to assemble (1) stuff sack
Operational Definitions - Stuff Sack Process Flow
Key Takeaway: Stuff Sack consists of (6) non-sequential processes, with PJ Flap being the most complex and time consuming
Operational Definitions - PJ Flap Process Flow Diagram
Key Takeaway: PJ Flap includes (4) parallel process, with the critical path represented by red boxes
Operational Definitions - Data Collection Plan
Operational Definitions - Data Collection Form
Key Takeaway: Used median times, with hi and lo times eliminated. Cycle times estimated for the production of (1) unit
Total Cycle Time by Stuff Sack Part - Total Cycle Time by SS Part â (1) Ship Set
Q: How do we know what it takes to meet customer demand?
A: Cycle Time Analysis
Key Takeaway: 20-25 minutes to produce (1) ship set
Cycle Time Analysis - 3K Ship Sets Per Month - Level 1 Analysis: SS Cycle Time by Part (3K)
Key Takeaway: Reducing PJ Flap and Patch WB cycle times are critical to success
Cycle Time Analysis - 3K Ship Sets Per Month - Level 2 Analysis: PJ Flap Cycle Time by Function (3K)
Key Takeaway: Sewing function appears to not meet customer demand
Cycle Time Analysis - 3K Ship Sets Per Month - Level 3 Analysis: PJ Flap Cycle Time by Process Step (3K)
Key Takeaway: Process cycle times meet Takt Time required at 3K/Mo.
Cycle Time Analysis - 3K Ship Sets Per Month - 3K Load Analysis, 100% Cross- Trained Staff
- Assume employees skills sets are interchangeable
- Does not recognize that employees have a different array of capabilities
- (8) employees with room to spare under Full Takt Time
- Test skill qualifications for each skill
Key Takeaway: (8) 100% cross-trained employees required
Cycle Time Analysis - 3K Ship Sets Per Month - 3K Load Analysis, Current Staff Size, Skills & Equipment
- Load allocations reflect operator specific training
- (12) employees required
- (2) sewing station operation at 62% of Full Takt Time
- (1) Two-person team RF Sealer
- (1) Two-person team Sonic Welder
- Higher levels of cross-training would allow more efficient use of staff
- Adding (1) sighted employee would free- up Faiza & Ernie for monitoring production and cross-training
Key Takeaway: Meeting 3K/Month production target is doable with existing shifts, personnel, skills and equipment
Cycle Time Analysis - 6K Ship Sets Per Month - Level 1 Analysis: SS Cycle Time by Part (6K)
Key Takeaway: The cycle time of 4 of 6 Stuff Sack parts exceed Full Takt Time, with PJ Flap and Patch WB needing the most improvement
Cycle Time Analysis - 6K Ship Sets Per Month - 6K Load Analysis, 100% Cross-trained
- 18-20 100% cross- trained employees required
- (3) sewing station for PJ Patch
- High need skills: Sew PJ Patches, Sew PJ Web loops, Part Marker
- 2nd Shift (4 employees) for RF Sealer and Sonic Welder; possibly (2) solo operators
- Adding (1) sighted employee is essential to perform tasks requiring visual inspection: Slitter, Inspection
Key Takeaway: Additional personnel and cross training are required
Cycle Time Analysis - 6K Ship Sets Per Month - 6K Load Analysis, Current Staff Size, Skills & Equipment
- Personnel skills is a barrier to load leveling
- (3) sewing station for PJ Patch
- High need skills: Sew PJ Patches, Sew PJ Web loops, Part Marker
- 2nd Shift (4 employees) for RF Sealer and Sonic Welder; possibly (2) solo operators
- Adding (1) sighted employee is essential to perform tasks requiring visual inspection: Slitter, Inspection
Key Takeaway: Additional personnel and cross training are required
Challenge Skill Criteria - Criteria: Slitter-sheeter machine operator needs to be fully sighted
- Q. Why does a slitter-sheeter operator need to be sighted?
- A. Because cause they have to visually inspect material for flaws.
- Q. Why is visual inspection of the material needed?
- A. Because the operator needs to see potential flaws.
- Q. Why does it need to inspected at the slitter?
- A. It doesnât, it just needs to be inspected.
Solution: Install flaw detecting cameras on light table or have inspection done by sighted employee
Key Takeaway: Drilling down of skill requirements can lead to unanticipated alternative solutions to cross-training, e.g. technology, changes in standard work
Walk Time and Layout Design Analysis - Stuff Sack Spaghetti Map - Before
Key Takeaway: A picture is worth a 1,000 words
Walk Time and Layout Design Analysis - PJ Flap Spaghetti Map - Before
Issues:
- No organic flow between work stations
- Presence of other departments disrupts flow and increases walking distances
- Bulk WIP dispersed throughout department
- Remote work stations preclude monitoring & increase walking distances
Key Takeaway: PJ Flap traffic pattern is representative of the department
Walk Time and Layout Design Analysis - PJ Flap Spaghetti Map - After
- Positioned equipment to reflect organic flow of WIP
- Centralized bulk WIP rack
- Introduced concept of a âMilk Runâ for supplying materials and picking up completed work
- Dedicated space for pallets and boxes
- (2) dedicated strapping stations
- (2) assembly/sort work stations not open surface tables
- Timely pick up of completed work orders assigned to Shipping Dept.
Key Takeaway: Centralized WIP and âMilk Runâ clean up traffic patterns
Walk Time and Layout Design Analysis -Walking Study Approach & Methodology
- Current work stations are lean to accommodate Blind operators
- Insignificant non- value added operator motion
- Walk distance impacts material handler
- Walking distances stepped off based on process flow diagrams
- Frequency of trips estimated by Supervisor
Key Takeaway: Operator motion is limited. Reducing wasted motion will not have a direct impact on the Stuff Sack cycle time
Walk Time and Layout Design Analysis -Walking Distance Before and After Proposed Layout â 6K/Mo.
All Parts:
- 77% reduction in walking distance across all Stuff Sack components
- 11 miles less walking for 6K ship sets
- Frees up 11 hrs. for value-added activities
Highlight:
- 96% reduction for PJ Flap
- 78% reduction for Patch Web/Buckle
Key Takeaway: (11) additional hours for value-added activities, e.g., monitoring production, cross training & troubleshooting
Bonus Improvements - Assembly & Sorting Work Station (Design Stage)
- Currently assembly / sorting functions are performed on 10â foldable tables that are too high for sitting and too low for standing
- Large open surfaces tend to attract clutter and are often used for unintended purposes
- Work stations specifically designed for assembly and sorting will be motion efficient and ergonomically designed
- Prefer standing design
- Existing work stations might be repurposed for Stuff Sack
- Currently assembly / sorting functions are performed on 10â foldable tables that are too high for sitting and too low for standing
- Large open surfaces tend to attract clutter and are often used for unintended purposes
- Work stations specifically designed for assembly and sorting will be motion efficient and ergonomically designed
- Prefer standing design
- Existing work stations might be repurposed for Stuff Sack
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Bonus Improvements - Strap Cutter Loader (Implemented)
- Original process involved loading a reel between the two wheels using a thin rod as the axel, then suing small clamps on each side. This process was performed on the floor (poor ergonomics)
- Since there was only (1) stand only 1 of 2 web cutters could be in simultaneous operation
- Original process took 17 min, the same as the time it took to run a cycle of strap cutting
Bonus Improvements - Strap Cutter Loader (Continued)
- The new Web Reel Holder feeds the material at the correct height. There are 2 loaders to allow both cutters to run simultaneously
- The white plastic discs that hold the reel in place are replaced by clear plastic to allow the employee to see when the reel is about to run out (currently being manufactured)
- The gas shock lifts the loading arm when the reel runs out. The locking latch holds the arm down when running
Bonus Improvements - Strap Cutter Loader (Continued)
- The âdonutâ allows for the two different size of reels to be loaded on either stand
- A ruler was mounted on the loader to check proper length
- New process time is 50 seconds, which is a reduction of 16 minutes, 10 seconds
Bonus Improvements - "Milk Runâ Cart
- Erratic and frequent sewing station replenishment and finished product pick- ups are significant contributors to wasted motion
- Introduction of a âMilk Runâ dramatically reduces wasted motion
- Milk Run 4x daily
New Staffing / Takt-Load Leveling Tool
Automated Operator Standard Work Sheet
Production Monitoring Form & Process
- Currently production is measured on a work order basis and does not accurately measure process cycle time
- Some work stations are equipped with manual or electronic counters
- Actual real-time production is not captured and monitored
- A new production monitoring form will be posted at each work station
- Supervisor monitors & manage production through out the day
- Create and maintain âRun Chartsâ to track individual and department performance
Observations & Recommendation
- Issue work orders on a ship set basis
- PJ Flap critical path must be protected
- Limit Supervisor production time to allow more time for value-added management activities, e.g. monitoring production, troubleshooting, cross training
- Maximize cross training opportunities based on ability
- Re-make defective bottom cutter die to eliminate gap
- Create multi-piece dies for patches and pockets
- Set-up and clean up should be performed by work station operators
- Modify In and Out bins at RF Sealer work station to keep production consistent with target production quotas
- Allocate completed work order pick-up to Shipping Dept.
- Designated spaces/equipment should be limited to intended use
- Reduce WIP storage to increase process velocity
- Control quantities produced by binning materials based on planned daily output.
- Replace (2) work tables with (2) work stations specifically design for part assembly and sort
Already Implemented:
- Create Strap Cutter Loader
- Activate 2nd strap cutting machine
- Mount strap measuring rule on strap cutter