Unit 3: LEAN WORKSTRUCTURING
Session 1: PULL PLANN ING
Push Planning Defined
• The traditional planning system is a push system.
– In this system work is pushed into production:
• Based on predetermined completion dates
• Regardless of whether workers are ready to start work
– It is an assumption-based vision of how the work will take place
– It confuses planning with prediction, leading to local optimization
Pull Planning Defined
• Pull planning depends on an understanding of the levels of readiness of
downstream activities.
• Work is scheduled for when it can be properly performed, not based on
predetermined dates, by those who will execute the work.
• Pull planning is used heavily in creating phase schedules in the LPS.
• In pull planning you start from a milestone and work your way backward
Lean Work structuring Defined
• Lean Work structuring (LWS) develops
the project’s process design while
trying to align:
– Engineering design
– Supply chain Variation
– Resource allocation (Mura)
– Assembly efforts
• LWS considers production workflow
during design and project planning.
View of Lean Workstructuring
Process Design
(How to assemble)
Product Design
(What will be built)
Work-structuring
Supply Chain
(How to
buy/fabricate)
2-5
How Is LWS Different?
• Much of what we do now is workarounds
• First Run Studies
– A cross-functional team tries to establish a standard to meet or beat
execution of that operation
– Follows the Shewhart plan-do-check-act cycle
• LWS vs. Constructability
– Constructability is a reaction to design, LWS is an influence on design
• LWS vs. Work Breakdown Structure (WBS)
WBS:
– is the progressive breaking down of a project into its component
parts
– It assumes that optimizing the parts will optimize the whole
LWS :
– is concerned with the whole, not the individual parts
Operation
Install Studs
Inspections
Processing
Handling
Wait
Install Electrical
Process
Processing
Inspections
Handling
Wait
Hang Drywall
Inspections
Processing
Handling
Wait
2-10
2-11
2-12
Lean Workstructuring Participants
• Who should be doing this?
– General and specialty contractors
• Project manager
• Foreman
• Team leader
– Supplier
– Owner (contract permitting)
– Architect (contract permitting)
Products of LWS: Operation Level
• Rough cut operations designs
– Decision to cast-in-place vs. precast
• Detailed operations designs
– How to form, rebar, and pour basement walls
– First run studies are utilized:
• Sequencing
• Material availability
• Video taping
Other Products of LWS
• Project organizational/contractual structure
– Each “chunk” of work is designed so that it:
• Can be produced rapidly and for a low cost
• Supports optimizing at the project level
• Delivers value to the customer and producer
• Supply chain configurations
– Look at how the project is connected to the external production
systems — Will it support just in time delivery?
Session 1 Summary
The pull planning simulation in this session illustrated the contrast between the
concepts of push and pull.
A push plan: is typically produced by a single entity, with little to no involvement
of those executing the work. This method results in a plan full of assumptions
about means and methods that usually is not reflective of what activities really
will take place.
A pull plan : is produced by those who will actually execute the work via active
collaboration and coordination. The pull plan is developed by working backward
from a target completion date, with tasks defined and sequenced as completion
of
one task releases work to begin on a subsequent task.
Session 2 Summary
• Lean Work structuring is the process of determining who will do what,
when, and how.
– The most benefit occurs when those decisions are made during early
design stages.
• Constructability is a reactive process to established designs.
• Work Breakdown Structure is good for understanding a project but not for
planning its execution.
