The computation of production efficiency
factors depends upon numerous variable which affect worker’s productivity in
actual job conditions at the project site. These variables vary from project to
project, and over place and time. Some of the typical factors affecting the
works production efficiency are given in the following. The values for changes
in the productivity rate or human effort are indicated for conceptual
purposes; these should be considered as guidelines and not mathematical rules.
Work complexity
A simple, familiar work, is easier to
execute than an unfamiliar, complex one. The extra effort needed for the latter
type of work, specially in the initial stages, may range from 10-100% of the
normal expected productivity.
Repetition of work
While the first- time execution of an
unfamiliar work needs extra effort and results in low output, the skill
acquired in the process, when utilized over a period of time to execute similar
works, improves productivity rate, especially when crew of workers is the same.
This improvement in productivity rate continues till a certain limit is reached.
The limit corresponds to the stage when
the crew acquires the necessary skill and becomes throughly conversant with the
process, and the work is performed at its peak productivity rate. This impact
of repetitive work on the productivity rate varies with time. nature of task
and the characteristics of the crew. As thumb rule, the improvement in
productivity rate can be taken from 5-15% for each repetition, from its
initially assessed rate of about 60-80% of the average output rate till it
reaches about 120% of the average rate.
Quality control
Stringent quality control is sensitive
projects, like in the construction of the nuclear reactor call for frequent inspections,
which involve elaborate documentation and is a time consuming task. They
increase the non-productive time of workers and in turn reduces productivity by
10-25%.
Equipment-intensive tasks
The construction tasks which can be
performed wholly or partly with equipments include excavating, handling,
transporting, filling, compaction, grading, hoisting, fabricating, precasting,
erecting, plastering, finishing, paving, trenching, cable-laying, pipe-laying,
and so on. Generally, special-purpose equipments are required for preforming
these tasks. The equipment-intensive tasks are less susceptible to productivity
changes than the labour-intensive ones.
Supervision
A supervisor manages his assigned
technical work as well as the workers under him. The accomplishment of tasks
economically and on schedule mostly depends upon the competence of the
supervisor, which in turn affects the worker’s productivity. An efficient and
effective supervisor can get a higher productivity from workers.
Climatic and weather conditions
Generally, under average weather
conditions with temperature varying from 40-700F and relative
humidity of 60%, the workers continue working at the same productivity level.
But extreme weather situations and seasonal changes like extreme hot or cold
climate, high humidity, and strong winds and rains affect both productivity as
well as the work performance.
Since construction projects are spread
over several months or even years, it is necessary to adjust the effect of
weather changes month-by-month on worker’s productivity as well as work
execution. This adjustment in productivity can best the assessed by experience
or it can be derived from available area productivity index.
Labour availability
The labour productivity also depends upon
the employment opportunities available in the market. If jobs are plenty and
labour is scarce, the labour productivity tends to become less. During a slump
in the construction market, labour is easily available while there is a dearth
of jobs. In such situations, employers can afford to be selective as hiring and
firing of workers become easy. In scarce job situation, the overall
productivity improves since the employers can then sort out labour with a light
productivity. There is also a tendency among labour to move to high-value,
large-sized projects since they offer them longer service, better job
opportunities and more stability.
Role of management
The project management has a key role to
play in planning and controlling productivity. It is responsible for specifying
the weekly target of work to be accomplished by the workers as well as how the
works are to be executed and using which resources.
During the execution stage, the management
provides the necessary resource support and closely monitors the performance.
Each week, it compares the planned target with the work accomplished, evaluates
variances, analyzes causes for variances, and takes corrective measures.
It provides feedback to the workers on
their past performance, and communicates performance improvement measures. It
suitably rewards the workers who have done exceptionally well, and keeps the
morale of the work force high. The productivity is bound to suffer if the
management fails to fulfill its role and obligations effectively.
