Project scheduling is a key aspect of project management as it covers the planning of what is to be done, when it is to be done, and who is to do it, and then monitors and updates what has happened. 

There are a number of project scheduling tools in general use e.g., MS Project, Primavera, ProjectCac.  However a lot of project managers have minimal exposure to project scheduling because this key project role is often performed by specialist Schedulers / Planners.

So exactly what is project scheduling?

People unconsciously schedule things every day of their lives.  In order to get to work on time at say 9.00am, it is necessary to schedule their morning activities from wake-up through to commuting in order to arrive at work on time. They must set aside sufficient time from the moment they wake up, to do all the things  they need to do to prepare themselves for work.

Multi Tasking – Image Here

Whatever they choose to do in preparation for work, they must estimate the time involved and subtract it from the planned work start time, in order to be able to arrive at the planned arrival time. All this activity is a form of simple personal scheduling.

Those of us who drive to work each day may have the opportunity to observe some interesting scheduling phenomena. Sometimes I have seen men shaving themselves with one hand and driving the car with the other. Other times we may see a woman putting on her makeup while sitting at the traffic lights. In addition to the physical activities of shaving and applying make-up, what they are doing is performing concurrent activities (i.e., driving and shaving) in order to arrive at work on time. It may be that things which they planned to do prior to leaving the house somehow did not get done. Now they are trying to recover from a “behind schedule” condition by performing those tasks concurrent with the drive to work.

So, as we mentioned at the beginning of this article, scheduling is something that we unconsciously do every day.

Why then should anyone bother to take time to study and apply the science of scheduling?

The answer lies in the degree of complexity required for achieving some outcomes. The personal scheduling that we all do in our normal way of life is very basic and simple. We do it automatically without giving it any thought.

So what is a schedule?

A simple definition is “A timetable for performing activities, utilising resources, or allocating facilities, which serves as a focal point for the management of the activities”.

Should the time come where we get involved in a project of considerable size, with multiple complexities spanning long periods of time and utilising considerable resources, our own or someone else’s, then it becomes essential that we become very good at scheduling.  It is also a good idea that we utilise existing scheduling tools to assist us to schedule complex projects, e.g., MS Project, Primavera, or ProjectCac are commonly used project management software tools.

Project Scheduling is a key control activity in project management and is often used as the baseline for Time and Cost Management.  If used for weekly progress reporting it becomes the hub of many critical aspects of project control and management.  

There is also a common language used by planning professionals that needs to be understood if you are going to use scheduling tools.  The following table lists a number of the common scheduling terms you will come across.

TERM	DEFINITION
SCHEDULE	A timetable for performing activities, utilising resources, or allocating facilities, which serves as a focal point for the management of the activities for a project. It may be represented in a number of forms including milestones, deliverables, activities, Gantt and PERT charts.
SCHEDULING	The act of preparing and/or implementing schedules.
GANTT or BAR CHART	A time phased graphic display of activity durations with the activity durations shown as horizontal bars
PERT CHART	A flowchart that shows all tasks and task dependencies of a project with tasks represented by boxes and task dependencies represented by lines connecting the boxes
EVENT	Something that happens at a point or moment in time
MILESTONE	An event of particular importance, i.e., a point in time representing a key or important event in the life of a project.
ACTIVITY or TASK	Something that occurs over time. The subject of the plan; that which must be accomplished
SUMMARY TASK or HAMMOCK	An aggregate activity or task that is effectively the sum of the tasks which are subordinate to it. Most PM software will automatically calculate the duration of a summary task as the length of time from the earliest to the latest of the subordinate tasks to which it is linked.
SEQUENTIAL	Activities or tasks that are done in a sequence, serial or series –  this means they are linked
CONCURRENT or PARALLEL	Two or more tasks that are done at the same time, or at times which overlap.
DEPENDENCY or CONSTRAINT	Things that cannot happen until something else happens first
CRITICAL PATH	The critical path is the series of tasks or activities that dictates the calculated finish date of a project. (i.e., they have no float or slack)
DURATION	The elapsed time to complete a project task or activity
FLOAT or SLACK	The difference between the time available for performing a task and the time required to complete it. If the total float for a task equals zero, then that task is on the critical path.
WORK	The effort spent on completing an activity or task, usually calculated in man-hours.
BASELINE	The project baseline is a copy of the schedule which was used as the support for the approved business case.   The approved schedule is copied into the baseline schedule which remains frozen until it is reset by any subsequent approval. Resetting the baseline is done when the scope of the project has been changed significantly, for example after an approved change of scope.