- According to McKinsey and the University of Oxford, large IT projects go over budget by an average of 45% and exceed their schedules by 7%, while delivering 56% less value than expected.
- A high-quality IT project plan covers the tasks of all groups involved: the integrator, the client, and other stakeholders as needed.
- Each task must be assigned to a specific resource, with effort estimated in hours or days and a validated capacity (vacation, statutory holidays, partial availability).
- The project plan also serves as a communication tool: a concise, visual version engages the team and keeps committees and management informed.
In IT projects, the quality of execution depends largely on the quality of planning. Too often, projects start with incomplete, imprecise, or unrealistic plans, leading to cost overruns, delays, and sometimes, outright project failure. The numbers confirm it.
“On average, large IT projects run 45% over budget and 7% over time, while delivering 56% less value than predicted.” Source: McKinsey and University of Oxford, study of over 5,400 IT projects
Why does the quality of an IT project plan determine its success?
A well-structured, realistic IT project plan that is shared by all stakeholders is a powerful lever for maximizing the chances of project success. Conversely, an incomplete or unrealistic plan creates blind spots, artificial pressure on teams, and impossible commitments right from the start. Here are the essential elements that define the quality of an IT project plan and ensure efficient, surprise-free execution.
What tasks should be included in an IT project plan?
A good project plan covers all tasks to be performed by all involved groups, including the integrator, the client, and, if necessary, other stakeholders. It is common to see plans that only account for the integrator's activities, which creates planning blind spots.
When a project relies on a management methodology, only tasks relevant to the situation should be selected. However, do not hesitate to supplement the methodology with specific activities: no methodological framework can claim to cover all the realities of a project.
How do you define dependencies and manage parallelism?
Dependencies between tasks are a critical element of plan quality: poor identification of sequence relationships or forgetting certain dependencies leads to major errors in the schedule and an underestimation of the project's actual duration. Rigorous validation of interdependencies contributes directly to the reliability of the planning.
Parallelism deserves the same caution. A plan that features too much overlap between major activities increases the overall project risk. Overlaps can sometimes be necessary to optimize the schedule, but they must be used judiciously so as not to overload teams or compromise the quality of execution.
How do you assign resources and validate capacity?
Each activity in the plan must be assigned to clearly identified resources, with the expected effort expressed in hours or days. This granularity makes it possible to verify if the plan is realistic and if the schedule accounts for the team's actual availability. Three rules apply:
- no task should remain without an assigned resource;
- no resource should appear without assigned tasks;
- planning must account for the actual capacity of resources by incorporating vacations, statutory holidays, and partial availability levels (e.g., 50% of the time).
Capacity validation is the key to answering the central question: is the plan achievable?
This validation assumes a rigorous estimation of efforts, an essential prerequisite: without a good estimate, it is impossible to build a reliable plan.
How do you protect the schedule against the unexpected?
To strengthen the robustness of the plan, it is recommended to include buffer zones—periods with no planned activity—that allow for absorbing the unexpected. These margins of maneuver increase the reliability of the schedule and protect the project against the inevitable contingencies that arise in any undertaking.
How do you make the plan a tool for consensus and communication?
An effective project plan relies on a clear consensus among key stakeholders: a real commitment to the plan, the schedule, and the execution approach, rather than a simple formal sign-off. This consensus fosters team cohesion and keeps stakeholders engaged throughout the project.
Beyond mere scheduling, a project plan is a strategic communication tool. It should be used to:
- track project progress;
- present upcoming key activities;
- rally the team around project goals.
For these communications, it is best to prepare a concise, visual version of the plan (simplified Gantt chart, milestones, main phases), typically in PowerPoint. Project management tools like Microsoft Project are perfect for detailed planning, but are poorly suited for presentations to committees or senior management.
What are the keys to building a high-quality IT project plan?
A good project plan is more than just an administrative exercise: it is a strategic lever that ensures alignment of efforts, risk management, and clarity of commitments. Rigour in defining tasks, dependencies, and resource assignments, along with achieving a solid consensus among stakeholders, forms the foundation of a quality plan.
Investing the time needed to prepare a realistic, comprehensive, and engaging plan maximizes the chances of delivering the project successfully, on time, on budget, and to the expected quality standards.
Frequently asked questions
What is a high-quality IT project plan?
A high-quality IT project plan covers all tasks for every group involved, defines dependencies between activities, assigns each task to a resource with verified capacity, limits risky parallel work, includes buffer zones, and is based on a genuine consensus among stakeholders.
How do you validate that a project plan is feasible?
Capacity validation is key. Each activity must specify the expected effort in hours or days, and the schedule must account for the actual availability of resources, including vacations, statutory holidays, and partial availability. No task without an assigned resource, and no resource without a task.
What is the purpose of buffer zones in a schedule?
Buffer zones are periods with no scheduled activity inserted into the timeline. They absorb the unexpected, increase planning reliability, and protect the project against the inevitable risks of any implementation, without forcing the team to reschedule all activities every time a variance occurs.
What tool should be used to present an IT project plan?
Tools like Microsoft Project are suitable for detailed planning but remain poorly suited for presentations. For committees and senior management, prepare a concise, visual version of the plan, typically in PowerPoint. A simplified Gantt chart, milestones, and the main phases are enough to get everyone on board.
- McKinsey and University of Oxford: Delivering large-scale IT projects on time, on budget, and on value (average cost overrun of 45% and 7% schedule slippage, 56% less value)
- PlanAxion: Project cost estimation, simple but unforgiving