• Work study

*Infrastructure Management and Construction*

direct time spent is related to the outputs [31].

screen numerous sites throughout the same day.

quits, attending to personal needs and breaks [33].

technique and work study technique.

*2.1.2 Physical recording technique*

study and work measurement.

work [30].

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

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

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

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

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

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

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

decided that direct labour cannot be used to estimate productivity [31].

**56**

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 impact improvement [32].

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

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 procedure is summarised in **Figure 2**.

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

#### • Work measurement

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

**Figure 2.** *Method study procedure.*

that time study provides a record of a particular operation, and not a check on an individual's performance [27]. The general procedure for work measurement is presented in **Figure 3**.

Work measurement can be carried out by the advanced method. Time study is the basic technique: Timing is usually performed with a watch unless the extremely accurate measurement is required, when devices such as the cine camera or portable tape machine may be used. The watch can be a good wrist or pocket type with a second hand, but a stopwatch is better and more convenient. The purpose of work study is to optimise productivity from the manpower and materials available, and since it is management's responsibility to see that the best use is made of organisation resources, it is, therefore, building managers who must be convinced of the value of work measurement application on building operations [27].

• Work measurement procedure

Work measurement includes structuring a progression of perception structures to incorporate pertinent undertaking data. Site information data is incorporated into the perception shape. Precedent: venture type, perception number, compelling beginning date, space limitation, assuming any, ordinary day by day working hours, and the site management level. Furthermore, a short depiction of the watched task, for example, the technique, divider type, adds up to floor zone, and the quantity of stories will likewise be incorporated into the form. At long last, the qualities of each watched exchange are featured as presented in **Table 1**: work measurement form. The fundamental motivation behind these structures is to reliably record the basic efficiency parameters of data sources and their related yields for the different aptitudes or exchanges and to reflect, to an expansive degree, the genuine conditions on destinations.

**59**

line learning curve is

**Figure 3.**

*Work measurement procedure.*

curve, which is calculated as

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

**Table 2** presents a typical analysis of work measurement data using the simple linear regression technique to investigate the relationship between the cycle numbers of the repetitive productive work input. The dependent variable is the skills worker recorded observed time productivity. A significant level of 5% was used to determine the relationship between skills worker inputs and cycle numbers by substituting the recorded observed time into the linear regression model equation: Y = α + βX (3)

From the regression equation, α and β indicate the intercept and the slope of the

β = (n∑xy − ∑x∑y)/(n∑x2 − (∑x) 2) (4)

α = Ῡ − βẊ (5)

In the regression equation above, α and β were used to calculate the regression

β = (n∑xy − ∑x∑y)/(n∑x2 − (∑x) 2), and α = Ῡ − βẊ (6)

In order to measure the significant of the skills (blockwork) productivity, the authors employed the application of the learning curve theory utilising the straightline unit model as presented in **Table 3**. The mathematical model for the straight-

Y = TI × (×) b (7)

b = InS/ln2 (8)

where y = cost and man-hours; T1 = cost, man-hours or time necessary to perform the first unit; x = cycle number of the unit; and b = slope of the learning

As depicted in **Table 2**, the slope and the intercept were estimated; thus

linear regression model. The slope and the intercept are estimated; thus

where y are the man-hours and x are the cycle numbers.

model for the skills productivity as presented in **Table 2**.

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

#### **Figure 3.**

*Infrastructure Management and Construction*

that time study provides a record of a particular operation, and not a check on an individual's performance [27]. The general procedure for work measurement is

value of work measurement application on building operations [27].

reflect, to an expansive degree, the genuine conditions on destinations.

Work measurement can be carried out by the advanced method. Time study is the basic technique: Timing is usually performed with a watch unless the extremely accurate measurement is required, when devices such as the cine camera or portable tape machine may be used. The watch can be a good wrist or pocket type with a second hand, but a stopwatch is better and more convenient. The purpose of work study is to optimise productivity from the manpower and materials available, and since it is management's responsibility to see that the best use is made of organisation resources, it is, therefore, building managers who must be convinced of the

Work measurement includes structuring a progression of perception structures to incorporate pertinent undertaking data. Site information data is incorporated into the perception shape. Precedent: venture type, perception number, compelling beginning date, space limitation, assuming any, ordinary day by day working hours, and the site management level. Furthermore, a short depiction of the watched task, for example, the technique, divider type, adds up to floor zone, and the quantity of stories will likewise be incorporated into the form. At long last, the qualities of each watched exchange are featured as presented in **Table 1**: work measurement form. The fundamental motivation behind these structures is to reliably record the basic efficiency parameters of data sources and their related yields for the different aptitudes or exchanges and to

**58**

presented in **Figure 3**.

*Method study procedure.*

**Figure 2.**

• Work measurement procedure

*Work measurement procedure.*

**Table 2** presents a typical analysis of work measurement data using the simple linear regression technique to investigate the relationship between the cycle numbers of the repetitive productive work input. The dependent variable is the skills worker recorded observed time productivity. A significant level of 5% was used to determine the relationship between skills worker inputs and cycle numbers by substituting the recorded observed time into the linear regression model equation:

$$\mathbf{Y} = \mathbf{a} + \beta \mathbf{X} \tag{3}$$

From the regression equation, α and β indicate the intercept and the slope of the linear regression model. The slope and the intercept are estimated; thus

$$\beta = (\mathbf{n}\Sigma \mathbf{x}\mathbf{y} - \Sigma \mathbf{x}\Sigma \mathbf{y})/(\mathbf{n}\Sigma \mathbf{x}\mathbf{2} - (\Sigma \mathbf{x})\,\mathbf{2})\tag{4}$$

$$\mathbf{a} = \mathbf{\bar{Y}} - \beta \mathbf{\dot{X}} \tag{5}$$

where y are the man-hours and x are the cycle numbers.

In the regression equation above, α and β were used to calculate the regression model for the skills productivity as presented in **Table 2**.

As depicted in **Table 2**, the slope and the intercept were estimated; thus

$$\mathfrak{F} = \{\mathbf{n}\Sigma \mathbf{x}\mathbf{y} - \Sigma \mathbf{x}\Sigma \mathbf{y}\} / \{\mathbf{n}\Sigma \mathbf{x}\mathbf{2} - \left(\Sigma \mathbf{x}\right)\mathbf{2}\}, \text{and } \mathfrak{a} = \bar{\mathbf{Y}} - \mathfrak{f}\dot{\mathbf{X}} \tag{6}$$

In order to measure the significant of the skills (blockwork) productivity, the authors employed the application of the learning curve theory utilising the straightline unit model as presented in **Table 3**. The mathematical model for the straightline learning curve is

$$\mathbf{Y} = \mathbf{T}\mathbf{I} \times \left(\mathbf{x}\right)\mathbf{b} \tag{7}$$

where y = cost and man-hours; T1 = cost, man-hours or time necessary to perform the first unit; x = cycle number of the unit; and b = slope of the learning curve, which is calculated as

$$\mathbf{b} = \text{InS/In2} \tag{8}$$

