Managing dependencies in project management

In project management, dependencies are relationships between tasks that determine the order in which they must be performed. They directly influence planning, risks, and the overall success of a project. Ignoring or mismanaging these dependencies can lead to delays, budget overruns, or even project failure. This article explores the different types of dependencies, their impacts, and best practices for managing them effectively.

What is a dependency in project management ?

A dependency is a logical link between two tasks or activities. It means that one task can only start or finish depending on the status of another task. These relationships are essential for establishing a realistic schedule and identifying potential risks.

Example :

Let's imagine a house construction project:

The task “Pour the foundation” must be completed before starting “Build the walls.”

The task “Install the windows” depends on the completion of the task “Build the walls.”

Types of dependencies

Logical (or internal) dependencies

These are inherent to the nature of the project and cannot be changed. They link tasks that must follow a specific order.

Finish-Start (FS): Task B can only begin once task A has been completed. Example: “Validate the design” (A) → “Begin development” (B).

Start-Start (SS): Task B can only begin once task A has begun. Example: “Launch marketing campaign” (A) → “Begin analyzing customer feedback” (B).

Finish-Finish (FF): Task B can only be completed once task A is complete.

Example: “Finalize the report” (A) → “Send the report to the customer” (B).

Start-Finish (SF): Task B can only be completed once task A has started. Example: “Start production” (A) → “Complete quality inspection” (B).

External dependencies

These arise from factors outside the project, such as material deliveries, regulatory approvals, or stakeholder decisions.

Example: “Receive building permits” before “Start construction.”

Discretionary dependencies

These are chosen by the project team to optimize efficiency, but are not mandatory.

Example: “Train the team” before “Launch a new phase of the project.”

Material dependencies

These involve shared resources, such as equipment or a key person.

Example: “Use machine X” for two different tasks that cannot overlap.

The impact of dependencies on a project

On planning 

Dependencies define the critical path of the project, i.e., the sequence of tasks that determines the total duration of the project. A change in a critical task can delay the entire project.

On risks 

Cascading delays: If a dependent task is delayed, all tasks that depend on it will also be delayed.

Resource management: Material dependencies can create bottlenecks if resources are not available at the right time.

On flexibility 

Rigid dependencies reduce the team's room for maneuver. Conversely, identifying discretionary dependencies allows the schedule to be adjusted to save time.

How to manage dependencies effectively?

Identify and map dependencies

Use tools such as Gantt charts or PERT networks to visualize the links between tasks.

Clearly document each dependency in the project plan.

Prioritize critical tasks

Focus efforts on tasks located on the critical path.

Allocate additional resources if necessary to avoid delays.

Anticipate risks

Identify external dependencies and plan for contingencies (e.g., additional time for deliveries).

Communicate regularly with stakeholders to avoid bottlenecks.

Use project management tools

Software such as Gouti allows you to model dependencies and dynamically adjust the schedule.

Communicate effectively

Hold regular meetings to monitor the progress of dependent tasks.

Clarify responsibilities for each task to avoid misunderstandings.

Conclusion

Dependencies are the backbone of a project: they structure its progress and influence its success. Proactive dependency management minimizes risks, optimizes resources, and ensures the project is delivered on time.