In project management, creating a clear and organized project schedule is essential for completing tasks on time. One key part of building this schedule is understanding the dependencies between different tasks. Dependencies show how one task is related to another, such as when one task must be finished before the next one can start. Understanding these dependencies helps project managers plan better and avoid delays.
In this blog, we will discuss which types of dependencies are most common in project schedules. We will explore what each type means and provide simple examples to help you understand how these dependencies work in real-life projects. Whether you are new to project management or just need a refresher, this blog will make these concepts easy to grasp.
Which Types of Dependencies Are Most Common in Project Schedules?
When working on a project, it’s important to know how different tasks connect and depend on each other. These connections, known as dependencies, help project managers plan the order of tasks and keep the project moving smoothly. There are several types of dependencies that are commonly seen in project schedules. Let’s explore them one by one.
1. Finish-to-Start (FS) Dependency
The Finish-to-Start (FS) dependency is the most common type you’ll encounter in project management. It means that one task (Task A) must be completed before another task (Task B) can begin. For example, imagine you’re building a house. You must complete the foundation (Task A) before you can start building the walls (Task B). In this case, the start of building the walls depends on the finish of the foundation.
Example:
- Task A: Write the content for a blog.
- Task B: Proofread the content.
You cannot start proofreading until the content is fully written. This is a clear example of a Finish-to-Start dependency.
Also read: What Can A Project Manager Do To Recognize Individuals’ Efforts On A Team?
2. Start-to-Start (SS) Dependency
A Start-to-Start (SS) dependency means that two tasks must begin at the same time, or one task can only start once another has started. However, these tasks do not necessarily need to finish at the same time. This type of dependency is often used when tasks can overlap, which helps in speeding up the project.
Example:
- Task A: Start designing a website layout.
- Task B: Start coding the basic framework.
In this example, coding can begin as soon as the design work starts, even if the design is not yet complete. Both tasks depend on each other to start but can proceed independently afterward.
3. Finish-to-Finish (FF) Dependency
Finish-to-Finish (FF) dependencies require that one task must be completed before another task can be completed. This does not mean the tasks must start together, but their completion is linked. This dependency type ensures that tasks are completed in a sequence that makes sense for the project.
Example:
- Task A: Complete the editing of a video.
- Task B: Complete the final review of the video.
Here, the final review of the video can only be finished once the editing is done. Both tasks might run in parallel, but the review cannot be completed until the editing is finalized.
4. Start-to-Finish (SF) Dependency
Start-to-Finish (SF) is the least common type of dependency in project schedules. It means that the start of one task depends on the finish of another task. While this may sound confusing, it’s usually used in very specific situations, often in complex projects.
Example:
- Task A: Start a new software system.
- Task B: Finish the operation of the old system.
In this example, the old system continues running until the new system starts. Once the new system is up and running, the old system can be shut down.
5. External Dependencies
External dependencies are tasks that rely on factors or actions outside the project team’s control. These dependencies are often linked to external stakeholders, such as suppliers, clients, or government regulations. Managing external dependencies requires good communication and coordination with external parties to avoid delays.
Example:
- Task A: Receive approval from a government agency.
- Task B: Begin construction work.
Construction cannot start until the necessary approvals are received. Since these approvals are outside the project team’s direct control, they represent an external dependency.
6. Internal Dependencies
Internal dependencies are tasks that rely on actions or decisions within the project team. These dependencies are easier to manage since they are within the control of the project manager and team members. Planning and clear communication within the team are key to handling internal dependencies effectively.
Example:
- Task A: Finish creating a marketing plan.
- Task B: Launch a marketing campaign.
The marketing campaign can only be launched once the marketing plan is complete. Since both tasks are managed internally, the project team can control the timing and coordination between them.
7. Mandatory Dependencies
Mandatory dependencies are tasks that must occur in a specific order due to the nature of the work or legal and contractual requirements. These dependencies are non-negotiable, meaning they cannot be altered without affecting the project outcome.
Example:
- Task A: Obtain a building permit.
- Task B: Start construction work.
Construction work legally cannot begin until the building permit is obtained. This is a mandatory dependency that must be followed.
8. Discretionary Dependencies
Discretionary dependencies, also known as soft logic, are tasks that are ordered in a particular sequence based on best practices or the project manager’s discretion. These dependencies can be adjusted if needed, allowing some flexibility in the project schedule.
Example:
- Task A: Complete a draft of a report.
- Task B: Conduct a team review of the draft.
While it’s a good idea to review the draft before finalizing the report, the order could be changed if necessary. This flexibility makes it a discretionary dependency.
Also read: What Are the Sustainable Development Goals of Education 2030?
Conclusion
Understanding the different types of dependencies in project schedules is crucial for effective project management. Each type of dependency, whether it’s Finish-to-Start, Start-to-Start, Finish-to-Finish, Start-to-Finish, or even external and internal dependencies, plays a significant role in how tasks are organized and completed.
By recognizing and planning for these dependencies, project managers can ensure that tasks are completed in the right order, avoid unnecessary delays, and keep the project on track. Whether you’re managing a small project or a large one, knowing these dependencies will help you create a smoother and more efficient project schedule.
