Posted By:Infra Bazaar
In construction activities employing machines or automated equipment to perform a specific task are a compulsory condition or constraints concerning their productivity and availability should be seriously considered at an early stage. The constraints are limited number of machines and automated equipment, productivity rates, weather conditions, duration of activities and inter relationships etc; it can have a major impact on progression. This kind of constraints could not be major criteria when tasks are performed by machines or usual equipment. However construction activities are performed by machines or automated equipment should have the above mentioned constraints points clearly and defined as early as possible. Three types of constraints affect the beginning and end date of activities.
The technological constraint defines the logical relationship between activities which can’t be changed unless the technology is changed. This type of constraints is the first and most obvious constraint to be defined. The application of machine or automated equipment can change the activities progression due to the change of work nature or construction methods.
As per CIRIA study, it has been found that providing installing or supporting the lining around the perimeter of tunnel to prevent movements of rock is important activity to able before any progression of the tunnel. The average time percentage for this obvious sequencing constraint alone is about 15.3 % of overall working time. Planning and scheduling of automated construction activities should account for this similar nature.
Managerial constraints are related to resources such as equipment, materials, and crews. It occurs when it is required to reschedule active resources for certain operations which cannot be made available as soon as they are needed or management feels that activities can be better sequenced or postponed from earliest starting dates.
These activities are performed by automated equipment; management has to consider many constraints related to nature of equipment and equipment management principles. There are several management factors that influence planning and scheduling of construction activities, as a result impacting equipment productivity, operating time, or production rates. These factors should be considered by management such as timing for equipment maintenance, security programs, inventory of parts, etc
The External Constraints are environmental, geological or safety concerns. Few automated machines or automated equipment is sensitive to subsurface conditions or changing weather and air pollution or causing noise when operated. Then, there will be a specific time table to perform the tasks. Few constraints are naturally difficult to identify when a network being developed, especially geological constraints.