1 Construction productivity

what is productivity

The construction industry is one of the most largest in the world economy from the other , with about $10 trillion spent all time on construction-related goods and services every year. However, the industry’s productivity has trailed that of other source for decades, and there is a $1.6 trillion opportunity to close the gap descion. The productivity growth is very slow in the construction industry which is creating a huge economic loss to the world economy. There is a direthen need to revolutionize the construction work industry. Construction industry accounts for 13 % of the world’s GDP but the sector’s annual productivity has only increased 1 % over the past 20 years. Whereas, productivity in manufacturing, retail, and agriculture has grown by as much as 1,500 percent.

Construction industry spending

Fig1 .1 Construction industry spending

1.2 Total factor & Labor productivity

As stated in the introduction, construction productivity is the relation between input and output. This relation is further divided into two categories: total factor productivity (TFP) and partial factor productivity (PFP). (Robles, Stifi, Ponz-Tienda, & Gentes, 2014)

Total factor productivity (TFP) is the summation of all the outputs and inputs, where as partial factor productivity (PFP) is one in which output is obtained using selective inputs.

TFP = total output / all input resource

TFP = Total output / Labor + machinery +equipment+ enaergy

Measurement of all the inputs to determine an output is not feasible, therefore it is impossible to accurately calculate TFP. To counter this, we use, partial factor productivity (PFP), also known as labour productivity.

Labor Productivity = Output Quantities / labor output

1.3 Levels of Productivity:

Construction productivity has been studied from different perspectives. Construction

productivity is the amount of work per unit of time that an engineering or project team To understand productivity we divide it into 3 segments or levels: activity, project & industry. Studying productivities at activity level help us to judge the performance of a project, studies at the project level aids in the assessment of the industry productivity & studies at the industry level shows the long term productivity trends.

2.4 Misconception about Productivity:

There is a misinterpretation that productivity is doing more at a very faster pace; to clarify this, there’s a better definition i.e. productivity means "producing better" and not necessarily "producing more". For e.g. To concrete a slab of 150 m^3 by 7 labour takes 5 hours in Project A and in another project (say project B) same volume of slab is concreted in 5 hours by 5 labours. The quantity of work stayed same which tells us that no project produced more quantity of work and the labour at project B was better at completing the work in the same amount of time, while being lesser in number. (data analysis in building construction productivity)

1.5 Green buildings & productivity:

Nowadays, productivity plays an important role in the increasing trend of green buildings in the construction industry. Green building poses a great challenge because its design & construction is more complex than those of conventional buildings, which usually leads to high design and construction costs. So, the contractor receives less profit from green buildings projects which demotivates him to opt such projects. This is where productivity comes into play. Improved productivity helps firm to maximize profits from green constructions. Moreover, long-term profitability and competitiveness can be obtained by the organizations & countries through increasing productivity.

long-term profitability and competitiveness can be obtained by the organizations & countries by increasing productivity.

1.6 Quality management & productivity:

Both quality and productivity go side by side. Quality work is obtained when it meets the customers’ demands while there is less wastage, fewer reworks, lower resources (capital) etc. and productivity concept is built on such principles. Edosomwan (1987) defined productivity and quality management as an integrated process. (data analysis in building construction productivit

1.7 Factors affecting productivity:

Many factors affect productivity. Factors has been divided in various categories depending upon the similarities among them.

Category	Factor
Project	· Constructionimethod · Complexityiofitheidesign · Drawingsiclarity · Projectiscale
Human	· Level of Skill and experience Human category · Ability to adapt to changes and new · environments · Labourimotivation · Workingiovertime · Number of breaks and duration · Worker´siintegrity
Environment	· Performingiworkiatinight · Influenceiofi workingi at height category · Motion´silimitationiinithe jobsite · Airihumidity · High/lowitemperatures · Raini · Highiwinds · Distance between construction sites and cities
Finance	· Inadequateisupplyior high cost of resources: workers (overtime work), materials, machinery, and money · Level of staff turnover/churn rate and Love and Edwards (2005) · Reworksiibecauseiofiion-site construction errors · Inflation/fluctuationsiiiiin material prices · Fluctuationsiiniiexchange rate · LateiPayments
Management	· Supervision,iperformance monitoring,iandicontrol · Competenciesiiiofiiiiiithe projectimanager · Lossiiiiiiniiiiiproductivity causediiiiifromiiiiichange orders · Lackiiiofiiicapabilityiiiiof contractor’siiiiiiiiiiiiiiisite managementitoiiiorganize on-siteiiworks · Adequacyiofiplanningiand riskimanagementiprocess · Adequacyiiofiimethodiiiof construction · Projectimanagementistyle · Lackiiiiiofiiiiicoordination amongiiiitheiiconstruction parties
Material & Tools	· Lackiiiiiofiiiiiitooliiiiiiand equipmentiinitheimarket · Adequacyiiiofiitechnology used · Lateiiiiiiiisupplyiiiiiiiiiiiof constructionimaterials · Materialiiiiishortageiiiiiiat projectisite

Table 2.0 factors effecting productivity

We have divide the above factors into two categories: tangible and intangible, for our study.

Tangible factors are those which can be measured at site. Intangible factors are those which can’t be measured physically or which will be measured through questionnaires.

1.7.1 Tangible factors:

Project category: Complexity of the design
Human category: Level of Skill and experience
Environment category: Day & night work
Finance category: Working overtime

We have shortlisted one (tangible) factor from each category.

1.7.2 Intangible factors

Management category i

Supervision, performance monitoring, and control

Competenciesiof theiprojectimanager

Lossiiniproductivityicausedifromichangeiorders

Lackioficapabilityioficontractor’sisiteimanagementitoiorganizeon-siteiworks

Adequacyiof planning and risk management process

Adequacyiofimethodioficonstruction

Projectimanagementistyle

Lackioficoordinationiamongitheiconstructioniparties

Relationshipimanagementidegreeiofiharmony,itrust, iandicooperation

Materials & Tools category

Lackiofitooliandiequipmentiinitheimarket

Suitabilityioriadequacyiofitheiplantiandiequipment used

Adequacyiofitechnologyiused

Lateisupplyioficonstructionimaterials

Materialishortageiatiprojectisite

1.7.3 Activities:

Factors of productivity varies from task to task. Construction project is a combination of several activities.

Following are the activities we selected: a) these are common in every project b) they are easy to measure

Form installation

Rebar installation

Concreting

Excavation

Brickwork

Painting

Plastering

Pipe fitting / Installation of pipes

Flooring (tiling)c

1.8 Work done in construction productivity:

Environment category: Day and Night. He did research on the labor productivity of 10 activities typically performed in both day and night shifts in urban sewer construction. Following are those activities:

Pavementicutting
Excavationi
Timberipiling
Steelisheetipiling
Formiinstallation
Manholeiconcreting
Rebariinstallation
Pipeilaying
Sandifilling
Asphaltipaving

The purpose of this research was to check how productivity of day time & night time affects various activities in site. The methodology for the research had two shifts : 9 hours (7 am to 5 pm) morning shift & 8 hours (8 pm to 4 am) night shift.

His research concluded that pavement cutting and timber piling had more productivity in daytime, whereas steel sheet piling and manhole concreting had higher productivity in nighttime. There was no significant difference in productivity between day and night shifts for the rest 6 activities. Lastly, this research helped us to prioritize which activity is to be performed and at what time of the day.