Construction Management, Accounts & Enterpreneurship Devlopment (General Engineering) (SSC JE)

The difference between the time available to do the job and the time required to do the job, is known float. It indicates the time by which starting of finishing of an activity on be delayed without affecting the project completion time. Float is associated with an activity.

Total float–It is difference between maximum time available and actual time required for the completion of the activity.
Total float = LF–EF
LF = Latest finish
EF = Earliest start

Free float–It is the amount of time by which an activity can be delayed without affecting the EST of the succeeding activity.

Independent float–It is the excess of minimum available time over the required activity duration.

Interfering float–It is difference of total float and free float of an activity it is also equal to the slack of head event of an activity.

The time which results in the least possible construction is known as slow time.
Normal time (tm)–It is standard time that a estimator will assign to an activityCrash time–It is that time before which an activity cannot be completed even by application of infinite number of resources. It is the minimum possible time in which an activity can be completed by assigning extra resources.

Project appraisal - It is a generic term that refers to the process of assessing in a structured way, the case of proceeding with a project or proposal. A good appraisal justifies spending money on a project. It is an important tool in decision making and lays the foundation for delivery and evaluation. It can give confidence that public money is being put to good use and help identify other funding to support a project.

Bar chart–
• A bar chart is drawn for time versus activity.
• The chart is a graphical representation of various activities involved in construction work.
• The bar chart is the technique of project management.
• The start and end points of the bar indicate the time of the finish and start time of the activity.
• The length of the bar represents the time required for the completion of an activity.

PERT (Program Evaluation and Review Technique)–The duration of each activity will be estimates using a three-time estimate reflecting the pessimistic, optimistic and most likely values of the duration.
Once this is accomplished the mean and variance of the project completion time. Knowing these parameters will enable due one to approximate the probability of completing the project in particular time frame and to estimate other "risk assessment" measures.
• The PERT is about incorporating the uncertainty of the duration estimate is the overall network analysis.

Bar chart–
• A bar chart is drawn for time versus activity.
• The chart is a graphical representation of various activities involved in construction work.
• The bar chart is the technique of project management.
• The start and end points of the bar indicate the time of the finish and start time of the activity.
• The length of the bar represents the time required for the completion of an activity.

PERT–
• PERT, which stands for "Programme evaluation and review technique".
• It is a project planning and control technique.
• It is an event oriented technique.
• It provides an approach for keeping planning uptodate.
• PERT analysis, event means start or finish of a task.
Event – It is stage or instant of time at which some milestone of project is achieve.

Bar chart also called Gantt. chart introduced by Henry Gantt. in 1917 AD.
• Gantt chart in its simple form, is a horizontal bar chart that shows a project plan on a timeline.
• The progress achieved of site is expressed in terms of percentage.
• It may be used for represent the resource requirement of a construction project.
• It provide a visual representation of entire project which shows exactly when each of the above activities is supposed to start and finish.
• It is also known as Bar Chart.

Free float–The delay which can be made without delaying succeeding activities. It affects only preceding activities.

Total float–The time span by which starting or finishing of an activity can be delayed without delaying the completion of the project.