Scheduling tools and techniques for Project Management
Scheduling tools and techniques
Project Managers can use a range of tools and techniques to develop, monitor and control project schedules. Increasingly, many of these can be applied digitally (using programs such as Excel, Microsoft Project and so on).
This is a horizontal bar chart plotted over time (e.g. days, weeks or months). Each activity is shown as a bar (its length based on a time estimate). Depending on task dependencies and resource availability, these bars may be sequential, or run in parallel. Each bar is plotted to start at the earlier possible start date. The plan laid out when the GANTT Chart was created can be compared with actual times taken (plotted below the planned time bars in the chart).
Schedule Network Analysis
The schedule network is a graphical display (from left to right across a page) of all logical interrelationships between elements of work — in chronological order, from initial planning through to project closure. As a project progresses, regular analysis of this network diagram is a check to ensure the project is proceeding ‘on track’.
Critical Path Method
The critical path of a project is the sequential string of activities that takes the longest time to complete, recognising any dependencies between tasks in this sequence (e.g. one cannot start till another finishes). Arrowed lines represent activities with circles at each end representing milestones (start and finish).
The critical path method (CPM) determines by adding the times of all activities on the critical path, the earliest time that the project can be completed
Non-critical activities have an earliest and latest start time (ES and LS, respectively) and an earliest and latest finish time (EF and LF, respectively). The ES and EF are found by working forwards through the project network and the LS and LF by working backwards. The difference between the LF and EF of each activity have zero float; they must be done when planned or the project overall will be delayed.
PERT (Program Evaluation and Review Technique)
PERT charts differ from CPM charts in the way times are calculated for activities. They allow better for uncertainty. For each activity, three estimates of time are obtained: the shortest time (SP), the longest time (LT) and the most likely time (MT). The estimate assigned for the activity is a weighted average of these three estimates. The formula is:
Expected time = (SP + 4(MT) + LT) /6.
A schedule can be shortened two ways:
• crashing: using more resources than planned on the task
• fast-tracking: adjusting the schedule so, mindful of task dependencies, more activities are done in parallel than was planned
This involves building in a time or resource contingency for tasks considered to be at high risk of overrun.
Resource tools and techniques
• Levelling: This involves adjusting the activities within the schedule so as to ensure there are minimal peaks and troughs in resource use. This ensures efficient use of resources. It also allows the Project Manager to direct resources, where required, to more critical activities.
• Critical chain method: Activities are planned in the light of their latest possible start and finish dates. The extra time that results between some activities can be used to better use resources.
• Resource histograms: This is a column chart that depicts the resources used on a project over time.
For more information on scheduling tools and techniques, view:
For more information on preparing a GANTT Chart, view:
For more information on the basics of using Microsoft Project, view: