Working SmarterPutting Best Practices to Work:
Transforming Logistics Capability into Readiness at the Marine Corps
Maintenance Centers
Maj Don Humpert, [email protected]
The Problem
• Example: MK-48 Power Unit– Fielded in ’85– Planned SLEP—never happened– Wearing Out– Of about 1700 fielded,
only 330 have been rebuiltor through enhanced IROAN
60%
65%
70%
75%
80%
85%
90%
95%
100%
1/7/00 4/7/00 7/7/00 10/7/00 1/7/01 4/7/01 7/7/01 10/7/01 1/7/02 4/7/02
Report Date
Rea
dine
ss (R
-Rat
ing)
Enhanced LVS Power Unit Non-Enhanced Power Unit (Minus MPS/NALMEB Fleet)
The Depot ContributionRebuilt/E-IROAN
No Depot/“Bare-Bones” IROAN
Average 12% Higher Readiness
And…
10
23
0
5
10
15
20
25
"Enhanced" "Non-Enhanced"
Average Annual OpFor Hours in Maintenance per Vehicle
But…
• Rebuild too expensive• E-IROAN not cheap either…• Production—(ahem)—sluggish
The Challenge
• Increase Throughput and make schedule without increasing Operating Expenses or sacrificing quality
TOC
ISO Lean
MRPII
Theory of Constraints**Five Focusing Steps**
1. Identify the Constraint
2. Exploit the Constraint
3. Subordinate everything else to the Constraint
4. Elevate the Constraint
5. Go back to step one (Avoid Inertia)
CONSTRAINT BUFFER
Process 1a Process 1b Process 1c
Process 2a Process 2b THECONSTRAINT
ASSEMBLY Process 3 SHIPMaterial Release
Drum-Buffer-RopeASSEMBLY BUFFER
SHIPPING BUFFER
Simplified DBR
Process 1a Process 1b Process 1c
Process 2a Process 2b Process 2c
ASSEMBLY Process 3 SHIPMaterial Release
OK Act
SHIPPING BUFFER
Production vs. Project• Production:
– Lots of queue time relative to touch time– Usually waiting for something to start– Usually decrease RCT by reducing time in queue
• Project:– Little queue time relative to touch time– Usually waiting for something to finish– Decrease RCT by removing safety time built into
individual tasks
Critical Chain Solution
• Use safety time for the whole project, not individual tasks
• Reduce WIP• Don’t batch inductions• Stop multi-tasking
• Buffer Management
Tasks
• Step 1: Tasks arranged in chronological order
20
161010
1616
Remove Safety Time
• Step 2: Safety time removed from individual tasks.
7 9
10
75 6
Resource Assignments
• Step 3: Resources are assigned to each task
7 9
10
75 6
Resource Sync
• Step 4: Resource demands are de-conflicted
7 9
10
75 6
Critical Chain
• Step 5: Critical Chain is identifiedCritical Chain
7 9
10
75 6
Project Buffer
• Step 6: Project Buffer added—50% of critical chain touch time, rule of thumb
Critical Chain7 9
10
75 6
17
Feeding Buffers
• Step 7: Feeding Buffers are placed between Critical Chain and non-Critical Chain activities
Feeding Buffer
17
7 9
10
75 66
Capacity Buffers
• “Drum resource” used to determine Capacity Buffer between projects
50% of Drum touch time (8 days) used as Capacity Buffer
7 9
10
75 66
7 9
10
75 66
7 9
10
75 66
17
17
17
Critical Chain + SDBR
Process 1a Process 1b Process 1c
Process 2a Process 2b Process 2c
ASSEMBLY Process 3 SHIP
New Materials
Feeding Buffer
Project Buffer
Shipping Buffer
7 9
1710
75 66
Capacity Buffer
1710
7 9
75 66
Production Management =(A)(Schedule) + (pull system)
• Critical Chain project management• Simplified Drum-Buffer-Rope production• Theory of Constraints “thinking”• MRPII “engine”
Implications for MRP
• Create Critical Chain in usual way • Modify item masters, routers and BOMs to reflect
the new lead times, routes and BOM indentures• Create Project Level Work Order and route using
the CC schedule• Run MRP to time phase materials and create a
dispatch list and shop orders with CC priorities• Create “Immediate Action” report for SDBR and
“Project Buffer Status” report for CC to manage by buffers
RCT
ResultPush (MRP)
WIP
Pull (MRPII+TOC)
Throughput
Maintenance Center Albany
Repair Cycle Time
020406080
100120140160180200220240
0 20 40 15 35 55 75 0 20 40 60 80Vehicle Number
Day
s
FY-00
FY-01
FY-02
Articulation Hitch Problems
Labor Hours
0125250375500625750875
1000112512501375150016251750
0 20 0 20 40 60 80 5 25 45 65 85
Vehicle Number
Hou
rs
FY-00
FY-01
FY-02
Engine RCT
0102030405060708090
100
0 20 0 20 40 60 80 5 25 45 65 85Vehicle Number
Day
s
FY-00
FY-01
FY-02
Engine Labor Hours
0255075
100125150175200225250275300325
0 20 0 20 40 60 80 1 21 41 61 81 101
Vehicle Number
Hou
rs
FY-00
FY-01
FY-02
• Sort: Get rid of what’s not needed. Be ruthless.• Straighten: Organize what belongs (Parts and
Materials).• Scrub: Clean everything (Equipment, Floors, and
Walls).• Standardize: Assign tasks. How will you keep your
shop clean and organized and who will do it?• Safety: + ALWAYS put safety first! +• Sustain: Audit shops. Create checklist.
Lean Thinking 6S Concept
Cable Shop—Before
Cable Shop—After
Body Shop—Before
Body Shop—After
MK-48 Readiness Contribution
“What-If” 2000• 6 per month per depot• 167 days/vehicle• $152K /vehicle
“General, for $137M we could raise readiness 12%, but it will take 19 years”
“What-If” 2003• 19 per month per depot• 51 days/vehicle• $120K /vehicle
“General, for $108M we could raise readiness 12%, in 2 years”
66***66**AAV – P & C Variants
146159213M88 Tank Retriever
3918No dataM149A2 Water Trailer
82282M970 Refueler
*63278M936 Wrecker
7048113M931 5-ton
49269MK17 Trailer
3822126MK16 Trailer
9569229MK15 Trailer
342356MK14 Trailer
111-16792-102180-240LAV
4853167MK48
ActualCritical ChainBeforeProduction Line
And Not Just MK-48s…
*No current production line.**AAV hull repair and assembly after receipt of hull from UDLP.***The AAV critical chain has been established to cover the work performed after the hull has been modified by UDLP.
9922AAV – C Variant
445AAV – P Variant
335M88 Tank Retriever
7717M149A2 Water Trailer
13**68M970 Refueler
0*06M936 Wrecker445M931 5-ton
123MK17 Trailer
122MK16 Trailer
122MK15 Trailer
338MK14 Trailer
7713LAV
393555MK48
ActualTOC TargetBeforeProduction Line
WIP Reduction
*Production line completed.**Awaiting one part to complete; received 23 Aug 02.