Lean Construction Assingment

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It can be argues that high competition levels exist in all types of industries regardless of the

product or service offered to the market, with an exception to some oligopolistic industries that exist

mainly in an national level. Among these industries is the construction industry as well, which can be

regarded as existing in a perfect competition. In 2007 reports published by the Department for

Business, Enterprise and Regulatory Reform, concerning the structure of the private construction in

UK, details of which are shown in table 1, supports the above argument of perfect competition.

Taking this into consideration firms in the construction industry in order to survive in a market

environment of significant competition have to seek ways to remain competitive and survive.

Size of the firm (nu of employees) Label Percentage of total (%)

1-13 Small 93.2

14-79 Medium 6.1

80> Large 0.7

Table 1 Structure of the private construction industry in UK in 2006 (DBERR2007)

Although few academic research improvements have been made directly for the construction

industry as a one of a kind type of work, construction firms should be willingly welcoming, by being

less risk conscious, the use of methods, philosophies and ways of doing from other sectors of the

economy (Gibson 2006), to transform themselves into a more healthy, sustained, productive and profitable organization.

One example of the takeover and use of other methods and philosophies, are lean and agile

thinking from the manufacturing sector, where the former has primarily been adopted from Toyota

(Koskela 2004). While many use the two concepts in the same way, differences do exist, both in type

of product, i.e. standardized or customized, and in the market volatility force applicable to. Both

philosophies goal is to cut costs enhance value generation and minimize the time delivering the

project. Agility has also the advantage of being more flexible and responsive to demand changes in

the market (Naim et al 1999). Also lean as regarded more efficient, gives more attention to cost

minimization, than agile does. Figure 2 shows the main differences of the two concepts, as a matrix to

show which strategy is most appropriate for which product and production respectively.

Figure 1 Applications of leanness and agility (Naylor et al. 1999)



Appl i¡ ¢ l£ ¤

¡ t¥

i¡

¦

i¡ ¢ i¡ t§ const ̈ © ction, is a way of managing const ̈

© ction as a product, i £

treating it in a manufactur ing manner (Bar telsen 2004), wit¥

a standardi ed product and low

var iability in demand, to allow a continuous, non interrupted f low, of mater ials, information etc,

minimi ing waste, destroying barr iers causing f low delays, generating value to t¥

e end user by

removing non value adding activities and decreasing t¥

e lead time. Tak ing account t¥

e complexity

and unpredictability of construction of construction (Bar telsen 2004), agile seems more appropr iate

since it allows for var iability of t¥

e product and also is more responsive in demand f luctuations

caused by it market volatility. Differences t¥

ough exist between construction pro jects and

manufactur ing products. Among these differences in the par ties involved in each and their measure

pro ject¶s dependability of each respectively, their level of complexity, in the uncer tainty of external

factors associated with their completion and many others (Pheng 2005). Mak ing a construction pro ject

associates many different par ties including, engineers of all professions, design and site engineers,

quantity and land surveyors, quality assurances, suppliers, contractors and subcontractors and many

others. Ballard (1998) one of the founders of lean construction claims that there are two ways of

mak ing construction, either by pointing out par ts and activities from the construction process which

can be regarded similar to the manufactur ing of products and use lean think ing, or customi ing lean

think ing to suit the dynamic and uncer tain environment of construction. It can be argues that agile

construction suits the second approach of what Ballard has stated.

Pr ior to the initiative of lean and/or agile pr inci ples in construction, companies either by

themselves or by consultation from third par ties need to understand and assess the current business

situation, in order to f ind areas of improvements. Therefore diagnostic tools are used which may

include direct observation techniques, f low visuali ation techniques, mapping of f low of information,

mater ials, people and processes, cause and effect diagrams to f ind the root of problems and many

others. Also current organi ational structure, quality measures, delivery times, roots of costs,

productivity and performance levels are also assessed (Watson 2003).

Much attention of lean think ing has been given in the supply chain management (SCM) of the

construction f irms. Supply chains are viewed as one of the highest contr i butors of waste and nuisance,

which in turn to costs, in construction and good management action can play a vital role in improving

and eliminating its effects (Vr ijhoef 1999). Lean think ing in supply chain affect positively all par ties

involved in the chain, in ways of value generation by deleting non value adding activities and

replacing them with value added ones and reduction in inventor ies, therefore at the same time

minimi ation of costs, decreasing the time duration of the pro ject and also to enhance harmoni ation

of the par ties involved by better communication and achievement of common goal. Use value stream

analysis is a way for reengineer ing the supply chain in construction (Arbulu 2003). For example a

general VSM is proposed by Arburu and his associates, for SCM in construction for the use of pi pe

suppor ts in power plants. Visual diagram was used to assess the current situation and with the use of

VSM eliminated non value adding activities (NVA), resulting in decreasing lead time (LT) and

increasing value adding (VA) percentage levels. Proposed initiatives include: maintaining strong

relationshi ps with suppliers, ear ly stages involvement in the initial designing phase of the pro ject andstandardi ation of products and processes in the SC. They also proposed the use of a data

communication tool, the µelectronic data interchange¶ to allow for needed information and data to be

communicated between all the par ties in the SC. Opposing factors though can make the proposed

model diff icult to be applied. Signif icant barr iers could include: the capacity availability by the

supplier(s), design engineers preferr ing not to involve others in the design phase, diff iculty existing in

the standardi ation of some products and communication problems among many different professions

and par ties. Another SC approach, for customi ed housing, was proposed by Naim (2002). But this



SC involved the use of both lean and agile thinking separated by the µdecoupling point , a point in the

chain where customization begins, i.e. the customer is involved. This point allows customization

through different combinations of the standardised products that flow before it. This optimizes SC

allows both concepts to be utilised to bring efficiency by using lean and also allows for customer-

driven model using agile, to give space for customer fluctuating demand and preferences. They argue

that µassemble to order SC structure is what suits best construction. Proposed initiates are similar to

Aburu (2003), mentioning also building adequate relationships with suppliers and subcontractors.

This approach suits UK housing industry were house customization is limited to fixtures, accessories,

internal and external finishes, mainly due to customer changing needs and the planning authority

which sometimes may oppose the variability of houses in certain areas (Naim 1999). Figure 2 shows

the improved model of SC of Naim and his associates.

Another lean and agile combination of system proposal, this time in the mechanical and

electrical construction part, gave insight on how, when these two are combined can have much better

results (Court 2009). This structure resulted in many positive outcomes, not only improvements stated

earlier but also costs reduction from labour, no recorded accidents, improved quality of work and

productivity performance improvements. Figure 3 shows structure.

Figure 2 Innovative construction supply chain (Naim 2003)



It can be seen that it utilizes another concept of management control, the ABC inventory system, to

differentiate materials by categorizing them together according to their consumption value (Slack

2009). In their structure, they also mention the use of the Last planner system (LPS) by (Ballard

1999), to help improve work flow reliability, by increasing levels of µpercentage of planned

assignments competed

(PPC).

It is difficult to mention all the different approaches made b y scholars to apply these concepts.

This is because these concepts are philosophies and not tools or models which are applicable in a oneoff initiative (Watson 2003). For this reason some applications are extracted from literature and

summarized in table 2.

Part of the

construction

process applied

Author

(s)Summary Relevant barriers

Building design Melhado

(1998)y Lean thinking

y Need for a coordination system in

the centre of the people involved in

design

y Sharing updated information

y Continuous feedback of problems

for ongoing improvement of the

design process

y Customized requests from

the client

y Communication

y Resistive forces to change

Ballard

(2000)y Argued that unnecessary or

negative iteration negatively affects

costs and time.

y Therefore for efficient design to

eliminate NVA loops

y Proposes ways to their

identification and elimination

y Complex design projects

need high intensity of

iterations

Figure 3 M & E lean and agile construction system (Court 2009)



Flow of work Sacks et

al (2009)y Visuali ation technique using

sof tware packages

y Combined with pull f low and use of

kanban system

y Information shar ing using reuse

economics

y More eff icient planning andscheduling of shor t term work

y Unpredictable events still

exist e.g. weather

y Construction site is

hazardous which limits theallowance to map/visualize

f low of work and people

Planning

process

Howell

(1994)y Lean pr inci ples to optimize the planning process

y Through the minimization of

var iation of f low of work, mater ial,information etc to maintainequili br ium between work that

µshould¶ be done and work that µcan be done¶.

y Many par ties involvedwhich makes f luctuation of

f low diff icult to bemanaged.

y Site is complex andunpredictable

y Complex pro ject planning

creates uncer tainty anduncontrollability of f low

Tabl

2 So

appli

ations of l

an p

in

ipl

s in

onst

u

tion



Howell, G. and Ballard, G. (1994) Implementing Lean Construction:R educing Inf low Var iation. In: 2nd Annual Conference

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Ballard, G. (2000). Positive and negative iterations in design. Proceedings IGLC 8 , p1-8

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Lean Construction Assingment

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