Dan Fauchier1 and Thaís da C. L. Alves2
Participation in LPS teaches-by-doing such foundational behaviors as collaboration,
transparency, long-term and short-term planning, making work ready, making clear
commitments, reliable promising, accountability and metrics – all in a clear, living
example of the colorful, visual workplace. LPS teaches teams the entire process of
Plan-Do-Check-Act (PDCA) and PDCA becomes woven into trust-building, because
using LPS (Planning) builds trust due to the making and keeping of reliable promises
across siloed companies and through behaving (Doing) in predictable, transparent and
monitored (Checked) ways and learning (Acting/Adjusting) together. Three main sets
of behaviors related to or promoted by the LPS were identified: building social
networks, addressing multiple needs in a dynamic environment, and treating
construction projects as production systems. As a contribution, examples from
construction projects implementing LPS are presented and linked to behaviors that
emerge from LPS implementation. Examples illustrating the three behaviors reveal
different instances in which these behaviors materialized and might have served as
“a-ha!” moments for the teams involved.
Last Planner System, lean behaviors, action learning, collaboration, reliable promises
The LPS was developed based on trial and error in practice and it elegantly addresses
principles related to production theories and organizational management, which are
discussed in this paper. This is a clear case in which practice has outpaced academia
and great effort has been done over the years to assure that the theory behind the LPS
is systematized. Much has been written about the LPS by practitioners and in
academic fora, most of them related to Lean Construction research and
implementation. While not explicitly discussed in academic papers, the LPS is
viewed by some researchers and practitioners simply as a tool, as isolated
components of the LPS system, or as a traditional planning method rebranded with
LPS-related names. However, there is more theory behind the LPS than is usually
recognized by many academics and practitioners. As a contribution to this discussion,
this paper presents examples from construction projects which have implemented the
LPS and links them to behaviors that emerge from LPS implementation.
1 Vice President, The ReAlignment Group, Ltd., San Diego, CA USA, email@example.com
2 Assistant Professor, J.R. Filanc Construction Eng. and Mgmt. Program, Dept. of Civil, Constr.,
and Env. Eng., San Diego State University, San Diego, CA, USA, firstname.lastname@example.org
PROMOTING LEAN BEHAVIORS WITH THE LPS
Research in Construction Management is usually skewed towards scheduling and
project controls given their contractual and operational importance to projects.
However, in the past 20 years or so, a host of studies have addressed the importance
of individuals and how they collaborate in construction projects (Laufer and Tucker
1988, Chinowsky et al. 2008) and how adaptive the managerial staff of a project (e.g.,
project managers, superintendents, foremen) has to be to match the environment in
which construction projects are built and the needs of multiple stakeholders (Laufer et
al. 1994). Another important subset of studies has addressed the need to treat projects
as production systems (Koskela 2000). A brief literature review on these topics is
presented to underscore how LPS promotes behaviors that fill gaps identified in
previous studies, and ultimately promote lean behaviors. The authors do not intend to
review the literature on LPS and would refer readers to papers published in the
Planning and Control sessions of this conference (available at www.iglc.net).
BUILDING SOCIAL NETWORKS
With the intent of shifting construction project management’s focus from the use of
tools and detailed schedules to managing projects as social collaborations, Chinowsky
et al. (2008) developed a Social Network Model for construction to highlight the
importance of fostering communication amongst project participants. They stressed
that “it is time to recognize the key role of individuals within project networks,
including the communication and trust that is the basis for achieving high
performance results” (Chinowsky et al. 2008, p.811). As individuals become more
knowledgeable about each other’s needs and constraints, the entire team becomes
more knowledgeable and prone to deliver better performance over time.
Along the same lines, collaboration and active participation of multiple trades in
the planning process is key for the successful implementation of plans. During
meetings, participants can see their opinion is valued, and how important that is for
achieving the project’s goals as a team, and openly express their assessments before
decisions are made. “Success of implementation is materially affected by the extent
and manner in which the implementors were involved in the decision-making process”
(Laufer and Tucker 1988, p. 343). The participation of foremen, superintendents, and
other stakeholders during the LPS process is a trait that differentiates LPS from
traditional planning methods which are grounded on the division of planning and
doing. Shoet and Laufer (1991) observed that foremen of productive crews make time
for planning. These foremen spend more time planning and viewing construction
documents when compared to foremen of unproductive crews; the time they spend
planning translates in better productivity in the field. This is in line with findings that
show LPS improves productivity of crews (Wambeke et al. 2011), because foremen
and superintendents in projects using LPS tend to be more involved with the planning
process. Finally, once plans are implemented, a new set of knowledge arises from
action and a new round of reflection and learning takes place among those involved
with defining and implementing the plans. This happens when, in LPS, daily and
weekly check-ins measure “Percent of Promises Complete” (PPC) and the root causes
of missed commitments.
In addition to building social networks, LPS implementation often includes other
behaviors that emerge in the deeply social environment promoted by the system:
• Coaching, leadership, open participation (teamwork, collaboration,
transparency, trust building. Teams undergoing LPS implementation
usually have some degree of coaching or leadership that emerges during the
process. Collaboration and trust also emerge from LPS implementation. These
behaviors are further fostered by a clear and visual workplace, which
promotes transparency and information sharing among team members.
ADDRESSING MULTIPLE NEEDS IN A DYNAMIC ENVIRONMENT
Laufer et al. (1994) suggest that planning is a multi-faceted process which has to
address multiple principles to be effective: 1. Hierarchy principle: “numerous
purposes for various users”; 2. Comprehensiveness principle: “numerous plans and
various formats”; 3. Continuity principle: “numerous timings and various time
horizons”; 4. Cooperation principle: “numerous participants and various modes of
preparation.” LPS addresses such principles by promoting a continuous review of
long/medium/short-range plans which are defined to match the information available
during the time the plans are generated, involving stakeholders who are part the of
value stream to deliver different phases of a project, and defining and communicating
the plans in different formats (e.g., meetings, visual work environment). Also, part of
this process is the Plan-Do-Check-Act (PDCA) nature of the LPS which promotes the
continuous review of goals, plans, and results to promote continuous improvement
and better match the project environment. This is especially relevant in complex
projects (e.g., hospital projects discussed later in this paper) where the amount of
effort spent on planning has to be adjusted to match the needs of ever changing and
tightly coupled systems.
In the LPS environment, pull planning brings together the final client and internal
clients of each major task, who are part of the effort to pull plan a schedule and make
everyone in the project aware of how their tasks interrelate and impact client tasks.
During the process, participants get rid of buffers that isolate tasks from one another
and from the internal and external clients requirements in terms of timing (Ballard
2000). The work indicated in Weekly Work Plans (WWPs) represents a network of
commitments which is founded on reliable promises made by project participants
(Macomber and Howell 2003). WWPs are the result of project participants’ work to
build this network of commitments over time through different levels of the LPS. The
constant definition, deployment and review of WWPs is a central element of the LPS,
which pulls information from field operation to adjust plans and make changes.
WWPs are essential to capture information that is available only after construction
begins, e.g., weather, availability of resources, precise coordination, design
clarifications, conflicts that might arise during production (Laufer et al. 1992)
In order to address the principles indicated by Laufer and Tucker (1988) the LPS
• Learning, continuous improvement and goal-driven behaviors – formal
and informal analysis of root causes and implementation of changes in short
time intervals exemplifies these behaviors.
• Systemic thinking/behavior – the LPS fosters a systematic process that goes
through a PDCA sequence and creates a stable sequence of tasks to be done in
certain time intervals. Teams identify what the clients’ need and value, define
work packages, define a work logic to create flow based on a network of
commitments, screen tasks for constraints, make promises, implement plans,
track plans to identify completed tasks and reasons for non-completion. This
all-stakeholder systemic sequence promotes transparency and accountability
week after week.
TREATING CONSTRUCTION PROJECTS AS PRODUCTION SYSTEMS
Lean construction implementation calls for a different look at construction projects as
production systems to be designed and managed considering three essential aspects of
production: transformation, flow, and value (Koskela, 2000). The transformation
aspect deals with the efficient management of resources to deliver tasks as expected.
The flow aspect promotes the view of construction as a network of interdependent
tasks that need to be managed an integrated fashion to promote continuous generation
of value to the client. The value aspect puts the project’s client front and center and
promotes the alignment of tasks to deliver what the client expects from the project.
To address these three aspects and promote the management of construction
projects as production systems, the LPS diligently works to shield production against
variation that might disrupt the flow of work (Ballard and Howell 1998). This diligent
work to shield production against variation through a structured planning and control
process yields good dividends.
Some production concepts embraced within the LPS include:
• Use of pull and promotion of flow – allows multiple stakeholders to translate
their knowledge into plans that consider real time information, project
participants’ collective expertise and requirements.
• Use of small batches – the release of small and defined batches of work
promote short cycles of detection and correction of problems, and higher
• Recognition of uncertainty and the need to continuously adjust planning
–metrics such as PPC and reasons for non-completion are tracked and
analyzed to prevent the recurrence of problems.
• Definition of clear production goals and metrics – this clear definition of
production goals help decision-makers establish plans that match actual
resources available and makes everyone aware of measurable goals used to
METHOD OF ANALYSIS
The initial challenge for any project or organization wishing to launch a lean journey
is how and where to start. The authors are a lean trainer/coach and an academic with
considerable experience in the field who have studied first-hand how – both
academically and practically – how projects and organizations throughout South
America and North America approach this challenge. The authors have collaborated
for several years and in their separate careers have deeply and continuously observed
over five dozen projects and organizations, each over a span of months and years.
The authors draw herein on those observations, citing specific examples.
In organizing the exposition of the paper, we have first identified three main
categories of lean behaviors and identified specific behaviors in each. Then examples
are iterated to illustrate how LPS enacts such behaviors in practice.
EXAMPLES OF LPS IN PRACTICE – BEHAVIORS RELATED TO OR
RESULTING FROM ITS IMPLEMENTATION
Drawing on the author-coach’s experience with fifteen teams on nine specific projects
in Northern and Southern California between 2010 and 2013, below are actual project
workplace examples illustrating the above lean behaviors. The examples are
organized in three main categories set forth above.
I – BUILDING SOCIAL NETWORKS
1. Collaboration. Because LPS requires that each step of planning is done by all
affected or typically involved foremen and superintendents (but also owners,
designers, consultants) there is an inherent expectation of collaboration.
Project Study A – Airport Terminal – In the first session, the LPS coach
initially encountered a group of trade foremen who had been under pressure to
complete the facility and, according to the General Contractor (GC), had begun
turning against each other demanding the GC give them first or exclusive access to
many of the shared work areas. Literally on Day 1 of the LPS sessions, the nature of
collaborative discussions occurring at the Milestone, 6-Week Phase Pull levels
changed the relationships from confrontational to collaborative by focusing their
attention on the process and handoffs, not personalities. This social realignment has
been observed on many occasions when LPS is introduced late in a troubled project.
2. Identifying value to customers. While establishing clear goals may be an
inherent characteristic of LPS, a consequential behavior that logically flows from this
is identifying what is valuable to customers. The end goal or milestone is likely a
valued item to the end user, but various interim goals are of value to other customers
including trades. The very act of identifying predecessors and constraints to the start
or finish of an activity in LPS defines value to owner of that activity – that person is a
customer of the trade or organization performing the predecessor activity (or
removing the constraint).
Project Study B – Medical Center – Although the multi-project medical center
was still three years from completion, when the Virtual Design & Construction (VDC)
director began orchestrating LPS Milestone pull sessions across the various projects
(hospital, specialty medical office building, central utility plant and site/off-site) with
the Owner’s independent commissioning agent, the Last Planners found additional
ways to drive value to the medical and maintenance end users by including them
more directly in the sessions, exploring and clarifying their deeper long-term needs
and taking the process far beyond what any of the parties had envisioned or
contracted. The dialogs around “the milestone wall” led to this.
3. Open participation/communication, transparency – Transparency among
Last Planners is essential to making reliable promises. In initial stages of
implementing LPS, often the parties approach each other without much trust and
“hold cards close to the vest”. They begin the process without disclosing all
assumptions and actual needs. As the process proves itself, trust increases, and with
Project Study C – Public Middle School #1 – A small team of prime
superintendent and Project Management (PM) and ten trade foremen initiated LPS
sessions and met weekly. By the third week the plumbing foreman, initially quite
resistant to “filling out stickies” began to disclose that the durations he had initially
required could be shortened because he saw others performing as promised. When the
Independent Inspector of Record began attending the sessions he disclosed that his
required 48-hour notice could be reduced to 24 hours because he lived a few blocks
away and could see transparently when work needed to be inspected to maintain
4. Trust building and reliable promising. While one could assert that reliable
promising is an inherent characteristic of LPS, in fact, the authors have found that
Last Planners do not necessarily begin making reliable promises. It is only when they
experience the impacts of others not making and keeping reliable promises, that they
begin to see the value in this practice.
Project Study C – Public Middle School #1 – The owner’s representative began
attending the LPS sessions for this Middle School and began observing that one of
the things impacting the trades’ meeting their commitments was lack of timely RFI
responses. Recognizing the value of the process and the need for good workflow, she
announced to the group that she would participate weekly, make out commitment tags
describing when an RFI response was needed to release their work, and then deliver
on her promises. She did what she promised, and went even further by bringing in the
Inspector of Record and persuading him to make commitment stickies, too and
further facilitate the flow of trade work.
II. – ADDRESSING MULTIPLE NEEDS IN A DYNAMIC ENVIRONMENT
1. Goal-driven behavior. The requirements of meeting commitments (promises)
which each Last Planner makes in the Weekly Work Plan (WWP) results in behavior
which drives toward the milestones/goals.
Project Study D – College Arts & Technology Centers – Having grown
accustomed to Weekly Work Planning (WWP) and filling out tags and to weekly
updates, PPC and variance discussions, an experienced LPS team found themselves
falling into the habit of just bumping their missed commitments to the next day or
week without consequence. The project completion date slipped. The success of
LPS was questioned. But when the team began adding their milestones prominently
to the WWP, and refusing to move the milestones, it forced them into devising ways
to revise their work to still meet their milestone goals.
2. Making clear commitments (understood by all). Human beings are not
accustomed to making clear commitments and Last Planners are no exception. When
they write down a description of the activities they commit to perform, they are often
sloppy in language and precision. When “a right to left pull” of activities and their
associated predecessors and constraints is done by the LPS facilitator, often the
predecessor is difficult to find because the two trades use different words to describe
it. It is only then that participants realize that they must use words and descriptions
that are clear and meaningful to everyone in the group. In so doing they also learn to
make clearer commitments.
Project Study B – Medical Center – Completion of the communication nerve
center (called a TER/TR) in a specialized area of a 12-story hospital involved a dozen
organizations, mostly prime to the owner. This specialized group had been meeting
for weeks making large TO DO lists but not making real progress completing the
work. A drop-dead date was only five weeks away. The group shifted to Phase Pull
planning emphasizing iteration of predecessors and handoffs, clarifying what each
commitment tag clearly included/excluded. As the end date approached, they shifted
to a Weekly Work Plan with daily tags and began daily check-ins. The clarity of their
commitments, expressed as daily tasks, allowed them to complete this critical nerve
center one day early.
3. Systemic thinking and deep analysis of cause. Humans often jump to
conclusions or rush to understand “why”, mistaking symptoms for causes. Asking 5
Why prompts us to dig deeper. But often in construction the root causes are multiple.
Project Study E – Prison Medical Center – One-third of the way through the
block wall construction on 15 housing units it was discovered that a critical
penetration detail was being missed and would require substantial rework. This
threatened to delay the fast-track, high-volume project and miss the delivery date.
Moreover, it could give rise to the owner questioning what other crucial details might
the team be incorrectly installing. Because the team had had such swift and early
success with LPS, they inquired as to what other lean tool might be utilized to solve
this problem and chose Root Cause Analysis. Countermeasures proved effective and
the Owner was reassured the team was fully in control.
Project Study B – Medical Center – When the rate of passed inspections fell to
89%, missed inspections frequently resulted in WWP activity “misses” which rippled
through activities on the Weekly Work Plans. “Inspections” had risen to third on the
list of Variance Causes. The schedule, the planning system, and their reputations
were threatened. Superintendents gathered to examine why they could not achieve the
95% goal. They looked to Root Cause Analysis to facilitate this inquiry, found the
three main root causes for the problems and devised an entirely new series of countermeasures.
4. Learning and continuous Improvement. We learn from our failures. This
team’s tenacity in trying to get it right gives the term Continuous Improvement a new
Project Study D – College Arts & Technology Centers – The project buildings
required that significant concrete pours occur for nearly a year before much other
work could occur. Mechanical, Electrical and Plumbing trades had many blockouts
and stubups that had to interface with massive concrete work. An initial token effort
at pull planning was made but was ineffective. CPM drove the schedule. Significant
delays by the concrete contractor were exposed as the root cause when, after a year of
stumbling, robust LPS was introduced and behaviors (good and bad) became
transparent. The contractor was fired. LPS continued with robust acceptance by
foremen. However, the construction manager was found to be ineffective at achieving
goals and when its contract expired, it was replaced. Again the trade foremen rallied
and with a new CM again rebooted LPS, this time learning to use Milestone
scheduling to establish the path to completion, then pulling from key milestones to
plot detailed WWP activities and sequences. The tenacity of the foremen and attitude
of continuous improvement prevailed. The project is headed toward successful
completion – late, but on a date certain and reliable.
III. – Treating Construction Projects as Production Systems
1. Establishing clear production goals. LPS begins with clear customer goals –
often expressed as one or, more often, many milestones.
Project Study E – Prison Medical Center – Halfway through a $640 Million
prison hospital, project leaders had been relying on CPM and Short Interval
Production Scheduling (SIPS), but needed to increase work-in-place from $1.5
Million/Day to $3 Million/Day. They implemented the Weekly Work Plan format for
each of 27 housing units, 3 hospital buildings and a facilities kitchen. Because the
clear long-term goal was “Start of Punch List” to occur in 18 weeks, they were able to
engage 70 foremen and trade superintendents in a series of thirty 18-week detailed
weekly work plans (the 4’x8’ weekly boards covered 3 walls of a huge site trailer,
then were tracked in Excel) with the clear end milestone framing a more innovative
sequencing of the activities. They finished six weeks early.
Project Study A – Airport Terminal – With four months to Substantial
Completion and three months behind in the construction of a major new airport
terminal, the General Contractor implemented LPS and declared a clear short-term
goal of Startup of Air Handler Unit #1 knowing that focusing on creating a
conditioned space would release significant internal trade work. The team achieved
the milestone within four weeks, then refocused to each of the remaining eight
AHU’s and finally to Substantial Completion. The project caught up the delays and
finished on time.
2. Long-term and short-term planning. Properly used LPS is fully time-scale
Project Study B – Medical Center – At the construction start of a Central Utility
Plant for a Billion Dollar medical center, the Superintendent implemented Last
Planner System with Milestone Planning for the entire project, then a series of 8-week
Phase Pulls to pull plan every step in the two year construction before construction
began. A Senior Project Engineer entered all the information into SureTrak, which
the Superintendent printed out and color coded to match the trade tag colors. For two
years they used this completely pull-planned scheme to populate and continuously
refine their Weekly Work Plans.
3. Promotion of flow and predictable handoffs between work stations or
trades. LPS can help sequence in weeks, days or hours, as seen in this very large
Project Study B – Medical Center – In the earliest days of what would become
three years of LPS implementation, the general superintendent and trade foremen
working in a 40’ deep pit installing piers atop caissons as deep as 90’ needed to make
up several weeks of time due to design complications. They broke the work down
into trade/day sequences, first among a group of piers, then pier by pier and saw that
the work had become so predictable, they could create per-pier stickies in hours, not
days and sequence their work and handoffs hour by hour on each pier. Doing this
they reduced the overall duration of that portion of the work by over four weeks.
4. Definition of clear metrics. Success can lull a team into lazy behavior.
Metrics can be the wake up call.
Project Study B – Medical Center – Metrics matter: both a Hospital LPS Team
and a Central Utility Plan LPS Team reached a point when their PPC (Percent of
Promises Complete) was reliably in the 70-95% range and, at different times
unrelated to each other, stopped tracking PPC. When their coach discovered this he
gathered the data from prior weeks, calculated PPC and showed them it had fallen to
55%. Not watching the “score” had created laxness and poor performance.
5. Promote flow and creating a clear, visual workplace. The clear visual
workplace is an inherent characteristic of LPS: colored post-its.
Project Study F – Cardiac Research Center – Inspired by colorful milestone
plans, phase plans, and WWPs on the walls of the large site trailer, the Superintendent
of a premier Cardiac Research Center moved the WWP boards with all the colorful
stickies out to the construction jobsite for 15-minute daily check-ins with yesterday’s
visual commitments marked off each morning. Workers could also see “the Plan”.
Project Study B – Medical Center – Inspired by the multicolored stickies on
their pull plans and Weekly Work Plan boards, several floor teams began devising
how else they could make their workplace visual. They posted floor-specific WWPs
on each floor, posted floor plans with a pad of colored post-its for any worker to post
questions or issues to be tackled daily by the Superintendent. Colorful VICO Line of
Balance reports began to be posted alongside the PPC and variance charts. The visual
workplace began popping up all over, inspired by the multi-colored LPS stickies.
6. Small batching. We encourage designers and constructors to think of smaller
batches in order to achieve maximum sequencing and flow of information and
materials. Last Planners best learn this lesson as a consequence of using LPS.
Project Study G – Medical EMS Remodel – The Design/Build team was led by
the Builder’s PM and the Architect with 10 engineers, consultants and trades
participating. The team had promised to cut the first of three phases of design from
seven months to four. They used Weekly Work Planning with swim lanes adapted to
design usage, with each entity having its own color tag, but placing those tags in the
swim lane of the other entity needing their work. They learned that they did not need
the full work product of another entity to release work of their own. “Just give me ‘x’,”
they would say. Instead of large periods of non-activity followed by frantic activity,
they were able to smooth the work flow by sharing information and drawings in small
batches, completing not one but three phases in the first four months.
7. The value of flow. Trade foremen (the Last Planners) inherently understand the
value of flow, as evident in initial training of foremen, whose faces express
understanding of the goal of LPS when it is described as helping them to achieve flow.
However, because in the broader world of design and construction flow is not
frequently experienced, Last Planners’ appreciation of the value of flow comes as a
consequence of experiencing it after several weeks of using the WWP.
Project Study H – Public High School Campus – After three sessions of LPS
planning, the project team realized that the plan for moving trades from one building
pad to the next did not take into account the constraints at the edge of the property
abutting the streets. Using pull planning, they tested and then resequenced the
circular flow into a zig zag flow moving into areas as early as possible, accounting for
constraints and still keeping the project moving.
Project Study I – Hospital and NICU Remodel – Within two months of his first
experience of LPS, this 15-year superintendent described how the weekly
collaborative conversations with his trade foremen more fully informed him on the
value of letting them choose how to flow their work in concert with each other. The
issues and challenges he said had previously kept him awake at night were now a
shared responsibility with his foremen, who knew better how, collectively, to achieve
the flow he knew could be possible.
8. Identification of waste. Even value processes like LPS can be stripped of
Project Study D – College Arts & Technology Centers – While identified waste
is usually in our work, a team that had been through real difficulty but had virtually
mastered LPS together and understood “pull” at all levels, challenged themselves to
freshly pull the last 8 months of the two companion projects to see if time could be
reduced. After a rigorous four-hour milestone level pull session, they decided that
pulling at the 6-8 week phase level would be wasteful, and went directly to the
Weekly Work Plan level and pulled from selected 6-week milestones.
Observation of fifteen teams on nine projects utilizing Last Planner® System has
demonstrated how participation in LPS teaches-by-doing foundational lean behaviors
discussed based on the literature review and the analysis of the projects. LPS is not
just a tool. LPS is the gateway to the panoply of highly desired lean behaviors. This
paper aimed to contribute to dialogue about the benefits of the LPS and how it
promotes behaviors conducive to greater collaboration and improved performance of
teams. Three main sets of behaviors related to or promoted by the LPS were
identified: I. Building social networks, II. Addressing multiple needs in a dynamic
environment, and III. Treating construction projects as production systems.
Ballard G. and Howell G. (1998). “Shielding Production: An Essential Step in
Production Control”, J. of Constr. Engng. and Mgmt., ASCE, 124 (1), pp. 11-17.
Ballard, G. (2000a). Phase Scheduling. LCI White Paper -7, available at
Chinowsky, P., Diekmann, J., and Galotti, V. (2008). “Social Network Model of
Construction.” ASCE, . of Constr. Engng. and Mgmt., ASCE, 134(10), 804-812
Koskela, L. (2000). An Exploration Towards a Production Theory and its Application
to Construction. Ph.D. Dissertation, VTT Publications 408. VTT: Espoo,
Finland, 296 pp.
Laufer, A., Howell, G.A., and Rosenfeld, Y. (1992). “Three modes of short-term
construction planning.” Construction Management and Economics, 10, 249-262
Laufer, A. and Tucker, R. L. (1988). “Competence and timing dilemma in
construction planning.” Construction Management and Economics, 6, 339-355
Laufer, A., Tucker, R.L., Shapira, A., and Shenhar, A.J. (1994). “The multiplicity
concept in construction project planning.” Construction Management and
Economics, 11, 53-65
Macomber, H. and Howell, G. (2003). “Linguistic Action: Contributing to the Theory
of Lean Construction.” Proc. IGLC-11, Blacksburg, VA, USA. 10pp.
Shoet, I.M. and Laufer, A. (1991). “What does the construction foreman do?”
Construction Management and Economics, 9, 565-576
Wambeke, B., Liu, M., and Hsiang, S. (2011). “Using Last Planner and risk
assessment matrix to reduce variation in mechanical related construction tasks.” J.
of Constr. Engng. and Mgmt., ASCE, 138(4), 491–498