Lean Construction and Process Mapping

• Applicability of Lean to construction

• Process Mapping

• Process standardisation

• Generic Design and Construction Process Protocol

What distinguish construction from

other industries?

• One of a kind? • Housing?

• So is manufacturing?

– Construction Standardisation/modularisation/prefab?

• Site based production? • Agriculture, mining, fishing which are early parts of

manufacturing value stream

• Temporary multi-organisations? • So are other project based industries

– Partnering

Two Characteristics together

uniquely defining construction

(Ballard and Howell)

• Fixed position manufacturing (assembly has to be

done on site)

• Rooted in place (standardisation is limited,

customer is linked to the site, temporary teams)

• Hence the characteristics of site-based production,

unique product and temporary teams

How to make construction lean

• Make the production of construction

components lean and minimise site-based

assembly.

• Develop lean techniques for dynamic

construction

Lean Thinking and Process

Mapping

• Only a small fraction of the total time and

effort in any organisation or project actually

adds value for the end customer.

• By defining value for a product or service

from the end customer's perspective all the

non-value activities (waste), can be targeted

for removal

flow Conversion

Towards Lean Processes

• Production and management processes must be

mapped and analysed

• None value adding activities (flow activities)

would then be subject to reduction or elimination

• Value adding activities (conversion activities)

must be made more efficient (Standardisation,

Technology)

Process Mapping

• Identification of non value adding activities

(mapping of existing processes)

• Standardisation (reengineering processes)

• Many standard ways by which a process

map can be presented (e.g. IDEF)

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5 1 5 200

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Receive request for

information

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application & request

for references

Wait

40 days

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group leader

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qualifications and

referees’ comments

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2

Secretary

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1

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team members

6

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10

46 days

Process standardisation:

Construction Project Process

• RIBA Plan of Work

• British Property Federation Model (BPF)

• New Product Development (NPD) process

• The BAA project process

• Generic Design and Construction Process

Protocol

Process Protocol

Consists of 10 phases

• Phase 0: Demonstrating the Need

• Phase 1: Conception of Need

• Phase 2: Outline Feasibility

• Phase 3: Substantive Feasibility Study & Outline Financial Authority

• Phase 4: Outline Conceptual Design

• Phase 5: Full Conceptual Design

• Phase 6: Coordinated Design, Procurement & Full Financial Authority

• Phase 7: Production Information

• Phase 8: Construction

• Phase 9: Operation & Maintenance

NPD Stage/Gate Process (hard and soft)

Lean and Planning

• Fast track and traditional project

management

• Allocation of Buffers

• Last Planner (Ballard)

Traditional Planning (CPM)

• Activities start after previous one finish

• Critical path is determined and becomes

focus of control

• Other paths have slack and hence provide

flexibility

• Resources are unlimited or can be delivered

to site on time

Traditional Planning (CPM)

• Planning techniques are about control

(preventing bad change) and neglects

breakthrough (causing good change)

• Delay of tasks, if not on critical path is ok

• If on critical, something must be done (put

more resources) otherwise project will be

delayed

Traditional Planning (CPM)

• Underestimation of effort result in fire fighting

and further problems.

• Overestimation of effort needed result in

complacency and low productivity.

• Emphasis not on why but what can be done to

mend the situation (fire fighting)

• Planning system performance is not measured and

failure is not analysed to identify causes

• Planning is not conceived as a system but as an

art/skills.

Need for shorter duration

(drivers)

• Added competitivity to contractor

• Enhanced cost

• Added scheduling flexibility (choosing

starting dates more freely, added time for

design and planning)

• Added capacity (shorter time means more

projects)

How can we shorten a project

duration?

How can we shorten a project

duration?

• Increase speed of tasks (increase more

resources, use of specialist subcontractors,

better technology, cut out non value adding

activities)

• Overlap activities (fast track) (e.g design

and construction)

• Reduce the number of tasks (prefabrication

and pre-assembly, combine activities)

Problem encountered when

reducing duration (fast track)

• Increase level of subcontracting mean

activities are not controlled fully and

process is not integrated.

• Variation of inflow (due to one of nature,

etc) are common (sensitivity to variation

increase with when overlapping)

REASONS WHY PLANNED WORK IS NOT DONE

Source: Ballard 1994

Traditional planning technique is

no longer appropriate?

• It hides relationship between design

(engineering), procurement and assembly (it

focus on assembly)

• It cannot cope with complexity of project

(difficult to match actual progress with

initial plan)

• Control affect human factors

Functions of buffers

• Compensate for differing average rates of

supply and use between two activities

• Compensate for uncertainty in actual rates

of supply and use (inflow variation)

• Allow differing work sequences by supplier

and using activity

Cost of buffers

• Buffers are expensive (storage space,

double handling, inventory management,

loss, buffer fill time, and idle inventories)

• Hard to size (actual supply and use rates

and unknown and they vary).

Arguments for buffers

• In current planning buffers do not exist and delays

and interruptions occur. Actual rates of

consumption are unknown because ‘normal rates’

includes delays due to waiting for resources.

• In order to find the uninhibited use rates we must

make it possible to work without interruptions.

• Allocating buffers has been proven to be a very

good thing and good managers hide resources in

the face of strong pressures to release them to

others for use.

Source: Howell and Ballard 1994

Source: Howell and Ballard 1994

Source: Ballard and Howell 1997

How to allocate buffers

• Between activities with different rates of

production

• Between activities with high inflow

variation (uncertainty) (need to assess

uncertainty progressively)

• Size of buffers should be limited to

minimum (better assessment, use of “Pull”

and “plan buffers”)

The Last Planner

by Ballard

• Provides a structure to planning (according

to level of details and size of window) and

gives power to the last planner

• An attempt to replace schedule buffers

(physical buffers) by planning buffers

(SHOULD, CAN, WILL, DID)

• Apply pull instead of push (downstream

activities determine size of workable

backlog)

Source: Ballard and Howell 1997

Source: Ballard and Howell 1997

Source: Ballard and Howell 1997

Planning System

Source: Howell and Ballard 1994

Managing Workable Backlog

Quality of weekly work plans

• Work is selected in the right sequence

(work in the sequence that best moves the

project towards its objectives - critical path,

workability)

• the right amount of work is selected

(amount of work that uses labour and

equipment capacity to the full)

• The selected work can be done (based on

workable backlog only)

The Last Planner:

Assessing quality of plan

• To determine where to intervene. The match

between output and directive at each level

should be measured and causes for

mismatched must be understood.

• Match between WILL and DID is measured

by Percent Plan Complete (PPC)

Performance Measurement and

Benchmarking

• Need for Performance measurement

• History of performance measurement

• Performance measurement frameworks

• Construction KPIs

• Benchmarking

Need for Performance

measurement

• Provides the information needed to take

business decisions

• Provides the bases and incentives for

continuos improvement

• Provides the information needed to perform

benchmarking.

History of performance

measurement

• The development in performance

measurement have progressed in two phases

• 1st phase concentrated on financial

measures (upto 1980’s) (lagging’ metrics)

• The second phase started in the late 1980’s

and involved non-financial measures

(leading indicators).

Performance measurement

frameworks

• The balanced scorecard (BSC)

• Performance measurement matrix

• The results and determinants framework

• Brown's framework of process metrics

• Performance pyramid

• The EFQM Excellence Model

• Construction KPIs

The BSC (Source: Kaplan & Norton, 1992)

Performance measurement matrix (source: Keegan et al, 1989)

Results and determinants framework (source: Fitzgerald et al, 1991)

Brown's framework of process metrics (Brown, 1996)

Performance pyramid (source: Lynch & Cross, 1991)

The business excellence model (source: EFQM, 2001)

Construction KPIs

• Client satisfaction: product & service

• Defects

• Predictability: cost & time

• Profitability

• Productivity

• Safety

• Construction cost

• Construction time

How to design a measurement

system

- Defining the strategic objectives of the company or a

process and determining how they are translated into

divisional goals and individual management actions.

- Deriving an appropriate set of measures by populating a

performance measurement matrix. - Instilling the performance measurement system into

management thinking. Critical here, is ensuring that the

measurement system actually drives day-to-day decisions

and actions.

Examples of impediments

- Fear of exposing poor performance

- Fear of exposing good performance

- Perception of more time and effort

- Fear of loss of autonomy

- Information overload

- Previous misuse and abuse of measurement

- Lack of skill and measurement masters

- Incompatible reward system

Benchmarking

Internal: compare processes within the organisations

Project/competitive: compares performance with its

competitors

External/industry compares performance with companies

in other but similar industries

Process/ generic: compare with different industries

Benchmarking process (source: Elmuti & Kathawala, 1997)