What is Scheduling?

Now-a-days, in construction industry, the parameters that define the success of a project are delivering the required facility, at the required standard (quality), within the agreed Time and Budget. A commercial construction company can grow only if it completes its projects in time and within budget. A schedule is prepared for achieving the said goals. To make a realistic schedule, it is important to take care of all the risks which can affect the construction of a project. The inter-departmental coordination is highly required. Each department should give its input in the preparation of Schedule. Such inter-departmental coordination will help the project to be completed in time and within budget.

In terms of Project Management Softwares, Scheduling is a tool by help of which the dates of an activity is calculated. The "dates" may be Early and/or Late Dates.

Common Mistakes in Scheduling:

Following is a list of few common scheduling mistakes which should be avoided (this list is prepared by keeping in mind the trend of schedule preparation in a software like Primavera, MS Project etc);

1) High Level Deliverables:

Any activity having a very large value of original duration can cause problem in scheduling and control. Generally, it is recommended to have maximum original duration of 60 days. Let us understand this by an example. Assume we have an activity "Excavation for Foundation" and the total quantity to be executed is about 500 cubic meters. It requires, say, 70 days to complete. Now, it may cause an error during scheduling and control. It is advised to divide this large activity into smaller one. There can be many options for dividing an activity into smaller activities. In this case, we may divide "Excavation for Foundation" into different areas (generally known as Functional Work breakdown Structure) like "Alpha", "Beta" etc. By doing this practice we will make sure that our schedule remains out of error.

2) Unrealistic Resource Pool:

During scheduling, it is required to create a resource pool which actually represents the number and amount of resources available for a project (in a company). It is utmost essential to create this resource pool. If a schedule is prepared without resource pool that will represent that the company has "Unlimited Resources" for the project; which is, of course, not practicable. It is very necessary to emphasize over "Critical Resources". Take an example of an Oil and Gas Schedule where installation of vessels is one of the (other) major activities. For the said activity, "Crane" may be a critical resource. If one emphasizes over non-critical resources then it will be considered as a scheduling mistake which should be avoided. Because the said mistake will create a problem in timely completion of a project as this will create a "Shortage of Resource" for a specific activity/activities.

3) Missing Dependencies:

While we make or create a schedule, the scheduling tool calculates start and finish dates of an activity based on the dependencies. These dependencies can be defined by defining a proper scheme of logical relationships. If not properly defined, it will cause an unrealistic schedule. Let us understand this by an example. Consider three major activities in the "Construction of Home" i.e. Foundations, Walls and Slab. Now if the construction of slab is depended on the construction of walls. Similarly, construction of walls depends of the construction of their respective foundations. If a scheduler will not provide list of all the dependencies, it might be possible that software will start the "Slab" activity before "Walls" activity which will be completely unrealistic.