A schedule ensures that tasks are sequenced logically, dependencies are accounted for, and resources are allocated efficiently. Techniques like the Work Breakdown Structure (WBS) and network diagrams help identify task relationships, while tools like the Critical Path Method (CPM) ensure project milestones are met.
One of the challenges in scheduling is estimating task durations accurately. If estimates are too aggressive, teams may struggle to meet deadlines, increasing the risk of burnout. Conversely, overly conservative estimates can make projects inefficient. Should teams rely on historical data, expert judgment, or a combination of both when estimating task durations?
Another major issue is task dependencies - some tasks must be completed before others can begin. A single delay in a critical task can have a domino effect, impacting the entire project. How do project managers mitigate this risk? Should they build buffer time into the schedule, or should they rely on fast-tracking or crashing techniques when things go off track?
I have worked on a project before that faced some major scheduling complications. In my case, we noticed very late in the project that a manufacturing device we had used early in the project had been malfunctioning. Consequently, we had to go back to basically the beginning of the project and redo many of our tasks. In this case, overestimating the length of certain tasks would not have really helped us. With that being said, it is probably best practice to still include some buffer time in your scheduling. Using a combination of historical data and recent expert estimates would likely lead to best estimations. Has anyone found any other useful tools for schedule planning and remaining on a schedule?
Accurate estimation requires a combination of historical data, expert judgment, and quantitative tools. In project management, accurately estimating activity durations is a cornerstone of planning and execution. It serves as the basis for resource allocation, cost management, and timeline adherence, directly influencing the project's success.
Techniques for accurate estimation:
1) Expert judgement: Professional experience can always help in judging and estimating the risks, shortcomings, and failure in the project. People who have done such a project will have hands-on experience of the nitty gritties of it.
2) Similar estimation: This is the information from previous projects. Any major risk and their management which have happened in the past can be helpful in planning for the present project.
3) Calculative estimation: This uses mathematical calculations to predict durations based on specific variables. Example if we need 2 hours to assemble one unit, we need 20 hours to assemble 10 units. Once the parameters are identified, historical data is analyzed to establish mathematical relationships or formulas that describe how these parameters impact the project’s outcomes.
4) Three point estimation: Three-point estimation seeks to provide a more realistic and reliable estimate by taking into account the inherent uncertainty and variability in project tasks or activities. Here 3 approaches are followed;
Optimistic- The best case scenario. representing the minimum possible time, cost, or effort required to complete a task. It assumes that everything goes according to plan, without any unexpected delays or complications.
Pessimistic: The worst case scenario representing the maximum possible time, cost, or effort required to complete a task.
Most likely- This is the most realistic estimate based on the project manager’s knowledge and experience. It represents the expected time, cost, or effort required to complete a task under normal conditions, considering both positive and negative factors.
5) Bottom up Estimating: Bottom-up estimating involves breaking down the project scope into smaller, more manageable components and estimating the key elements required for each component. These estimates are then aggregated to determine the overall project’s duration, cost, and other needs. It helps in accuracy, transparency, and detail.
To mitigate the risk of task dependencies, choosing between fast tracking and crashing depends on the project's needs and available assets. Fast tracking is often the first approach when time is pressed, as it doesn’t typically require extra resources—just a reshuffle of activities to happen in parallel. However, it increases the risk of errors since multiple tasks are being handled at once. Project crashing, on the other hand, is resource-intensive, calling for extra hands or hours, but it can be more controlled and less risky in terms of task management. The domino effect in project planning is a reality that project managers must embrace to achieve successful project execution. By understanding the significance of predecessors and successors, project managers can effectively allocate resources, manage dependencies, and maintain the project’s momentum.
In almost every case the requirement is not well defined from the beginning. Often add-on tasks or requests become part of the actual pipeline. It is better to have buffer time in the schedule.
