Basics in Building Construction

Basics in Building Construction 4(2+2)

Lesson 31 and 32 : Construction Project Management

Methods Of Planning And Scheduling

Conventional Methods

Different conventional methods that can be used for planning and scheduling the project are Gantt or Bar chart, Milestone chart and Flow chart.

1. Gantt or Bar chart

Gantt chart was introduced by a consultant named as Henry L. Gantt prior to World War-1. This method is also commonly known as bar chart method. It is a simple method which can display time schedule of different activities in the project as well as make a comparison between actual performance and the schedule. In this case a project is divided into different jobs or activities which are represented by horizontal bars on a time scale. The beginning and end of the bars represent the time of start and completion of the activity whereas its length represents the total time required to complete the activity. On the date of reviewing progress, the bars are shaded to indicate the portion of the work completed. Hence with the help of this chart, it is possible to know the scheduled target as well as the actual progress for different activities at the time of review. This in turn enables one to identify whether a particular activity is behind schedule, ahead of schedule or on time.


The Limitations of Gantt or Bar chart

1. It does not indicate the inter relationship between various activities
2. It does not indicate the effect of the activity behind schedule or ahead of schedule on the overall completion of the project.
3. It does not indicate which activity is critical and which has spare time.
4. It does not give any idea of what exactly is completed on the date of review, and one has to only guess very broadly as to how much of the work (in terms of percentage i.e 50% or 75% etc) is completed.
5. In case of bar chart, it is difficult to optimize the use of resources
6. Bar charts do not prove useful in research and development projects where number of uncertainties are involved and it is difficult to allocate definite time for different activities.In case of bar charts only major activities in the project are exhibited. If all activities of the project are to be shown, it becomes very lengthy and cannot be used with ease.



Thus, bar charts are not considered useful for big projects. Despite the above shortcomings, Gnatt or Bar chart is still widely used for planning and scheduling of small sized conventional projects (construction, manufacturing etc.) since it is simple and can be easily understood.



2. Mile stone chart

This chart was developed around 1940. This chart is basically similar to Gantt chart except that it shows important events of milestones (in the form of vertical arrows) on the horizontal bars representing the activity. The system of reporting progress becomes definite in this chart.

Limitations of Milestone Chart:

1. It does not show inter-relationship of milestones and does not depend on different jobs.
2. It does not allow the effect of one milestone being behind schedule on the overall completion of the project.


3. Flow chart:

It is a brief and simple graphic representation of flow chart showing relationship between activities and at thee same time contains events and milestones.

Limitations of flow chart

1. It does not provide information regarding time of completion of activities
2. It does not show the effect of slippage in one activity over the total period of completion of the project.