**2.1 Techniques used for measuring time and motion study**

There are three major methods used in the measurement of time and motion study (work study) in construction productivity [29]:


### *2.1.1 Visual recording method*

Visual account is a strategy utilised in observing the execution of specialists on destinations persistently, and it may be considered as a pioneer in the use of visual chronicle method for efficiency checking determinations [29]. Parker and Oglesby [30] saw that this procedure includes the utilisation of photography time-slip with the application of a camera concentrated on a work territory and a photo is taken at precise time interims extending from 2 to 8 minutes. This strategy has a few advantages over others giving right, enduring and unquestionable records that can be valuable to teach determination of construction claims and contract contradictions, assessing workforce skills performance and evaluating the productivity of construction methods. This technique is related with a few burdens, for example, creating distress between the labourers being continually watched, lacking inadequate coverage area and the prerequisite for various cameras on huge destinations.

Another kind of visual recording approach is the utilisation of tape recording framework in estimating workforce abilities execution. It has related elements of a task yet catches all or most concurrent exercises considering less eyewitnesses

nearby. One of the burdens of this strategy is discovered that the procedure is a costly technique; it requires taught watchers to be available on location to monitor and record the work finished by specialists. The rudimentary methodologies utilised in this execution are activity sampling, visiting the site every day and consistent observation. Sampling activity strategy is otherwise called sampling work [30].

Activity sampling technique can be portrayed as a sporadic recognition methodology that incorporates seeing a little degree of assignment events that is adequately tremendous to have a numerical consequence. Regardless, it includes an eyewitness who may stroll around the project site and record workforces' events, it is used to pass on a gadget for describing how the pros commit their time on attempted site, and it is occasionally expected that work accomplished, or yield is identified with the measure of period spent on direct work [30]. Activity sampling technique has been used widely and tested by several researchers, and important results were presented in many technical articles; one of the main importance of the method is that several workers can be concurrently observed by an observer on site, while the main drawback accompanying this method is the assumption that the amount of direct time spent is related to the outputs [31].

An investigation carried out on the US plant construction using an extensive analysis of the data collected by activity sampling established there was no relationship among the direct working time spent and the outputs. The investigation found that work sampling technique does not differ between actual and busy work and decided that direct labour cannot be used to estimate productivity [31].

Another type of activity sampling technique is the daily visit technique which is also known as intermittent observation method that encompasses the observer collecting data from site visit on a day-to-day basis [32]. According to Naoum and Hackman [32], finished site work or construction is visually checked by the observer and, if appropriate, marked on drawings; this technique has numerous importance, and if building sites are in near closeness to one another, the viewer can screen numerous sites throughout the same day.

Significance of this strategy is that it evades the turmoil joined by workforces being watched and checked and underpins in maintaining a decent relationship among the watcher and site labourers. The information assembled by this procedure relies upon the exactness and precision of the information given by the site specialists; the steady perception strategy can be isolated into perception by direct technique and work study technique.

#### *2.1.2 Physical recording technique*

Direct observation technique can also be described as a physical method of observation that consists of a researcher physically observing the site for the total duration of the operational day and the observer concentrating his devotion on a gang of skilled craft members and recording direct and contributory time spent on the work and the period that is not consumed at work such as late starts and early quits, attending to personal needs and breaks [33].

This technique offers a correct data and is very advantageous in determining the time input distribution used to accomplish certain outputs. The major disadvantage of this method comprises dissatisfaction and mistrust between the workers or group being constantly monitored, which might cause incorrect or inflated productivity, and also, on big project sites, it might necessitate more than one observer to efficiently observe the tasks rendering this method expensive [34]. There are three parallel approaches to physical recording technique, namely, work study, method study and work measurement.

**57**

*Measuring Infrastructure Skills Productivity DOI: http://dx.doi.org/10.5772/intechopen.85953*

The term "work study" considers the parallel strategies of method study and work measurement, which by an efficient method of examination and enhancement try to get the most ideal utilisation of human and materials assets [27].

The work study strategy is another related procedure like the immediate perception technique; notwithstanding, it shifts in the season of checking by the watcher on location; this technique, perception identifies with the work grouping of the undertaking analysed (British standard glossary, BS 3138). Work study can be all around characterised as an association benefit dependent on those techniques; particularly work measurement and method study strategy contemplate what is utilised when exploring human work in all background, and this can prompt the precise examination of the considerable number of capitals and variables which aggravate the viability and economy of the condition being inspected, so as to

Work study bolsters the parallel method study and work measurement strategies, which is a methodical technique for acquiring the most ideal utilisation of material and HR. It is a standout among the most possibly helpful apparatuses of the management. Conventional men can accomplish extraordinary outcomes by limiting squandered exertion and time and setting an appropriate standard of execution.

Method study measures the adequacy of the strategy and work technique procured to convey frameworks of examination designed for the headway of efficiency measures and surroundings of working [35]. The aim of method study is to evaluate the best method of doing work in order to recommend the best efficient technique of production. Although the detailed analysis may become more complex, the basic

The initial approach to this method is to first select the type of work that will impact the overall productivity of the skills workforce. The factors to be considered during the selection are economic, technical or human. Economic factors can include "bottlenecks" that can influence other activities. For example, form working on reinforced concrete-framed buildings, the operations can involve lots of labour/plant or the transportation of materials through a long distance like excavation of long hauls and repetitive work like building. There are always technical

A work measurement complements method study in order to derive the maximum benefits from a systematic study of work activities. While method study is related to the approach in which work is performed, work measurement is interested with the human resources involved in the job. Although work measurement and method study are interdependent, they cannot be separated from each other. The mental approach of work study is primarily the application of common sense, and assessment of the expected time needed to carry out a specific task by work measurement, because of the special technique employed, is mainly the field of the trained and experienced expert. Nevertheless, a project manager must have an adequate understanding of the principle involved if he is to employ work study successfully. Since work measurement seeks to reveal the shortcomings of management and to show up the behaviour of workers, it is often met with resistance so that an understanding of human factors involved is important. It is worth noting

issues, but these issues must be resolved by a consultant specialist [27].

• Work study

impact improvement [32].

• Method study

procedure is summarised in **Figure 2**.

• Work measurement
