What are the Dependency Types in Project Management?

There are several kinds of dependencies that you could run into when managing projects inside a professional company. It's crucial for project managers to understand the various project dependence types and how to operate inside each one.

Project management dependencies significantly influence the development of the project schedule. This may enable you to manage projects more efficiently and get better results. This article will teach us about these dependency types in project management to grasp our projects well.

What is a Dependency?

A dependence in project management refers to a set of interconnected activities. We may design and monitor intricate task interactions in projects using these dependencies. There are numerous task dependency types to select from depending on the project. However, they all have the same objective: to explain the order of the project activities and their relationships with one another.

Importance of a Dependency

Dependencies are a huge help when it comes to project scheduling. The benefits of modern living include the ease with which anything can be accomplished through software. Project managers use Gantt charts nowadays to display dependencies.

Dependencies aid project managers in allocating the proper resources to the appropriate activities at the appropriate times. It also makes it easier for them to prepare ahead of time and fulfill deadlines. Sometimes a job for a project needs to be completed before it can be moved forward. Understanding how dependencies operate will enable you to create a clear and consistent strategy as a project manager even before the project is started.

Types of Dependencies in Project Management

Logical Dependency

Logical Dependencies are also known as causal dependencies. These dependencies are intrinsic and are an unavoidable component of the project. Since logically dependent jobs typically require the output of earlier tasks as an input, concurrent execution is not possible. Think about making a cake for your assignment. You can't begin the procedure if you don't have all the components.

Mandatory Dependency

Mandatory Dependencies are often built into the nature of the task and are occasionally mandated by contract or legislation. These require that the task be completed in a specific order. They go by the name Hard Logic as well. They cannot be disregarded since they are inherent or mandated by law. For instance, you must first build the walls before laying the ceiling.

Discretionary Dependency

Discretionary dependency may also be referred to as preferred, preferable, or soft logic. The project management team will decide how to handle this dependence. There are frequently several ways to do a task, and the project management team selects whether to use one approach exclusively or rely on the others. The choice is based on their knowledge, recommended methods, or lessons learned.

External Dependency

External dependencies are identified between project and non-project operations. The project team is in charge of all project-related tasks. People outside the project team carry out the non-project activities. The project team typically has little influence on non-project activities; therefore, their failure to occur might disrupt the project timeline.

Resource Dependency

This dependence stems from a project restriction since it deals with the accessibility of shared resources. When two tasks depend on the same resource to be completed, they are said to be interdependent.

Internal Dependency

Internal dependencies are specified between two project tasks. The project team often has total authority over all project-related operations. Internal dependencies may be discretionary or mandatory. The project management team is responsible for these dependencies internally and has total control over these processes. The project management team makes this decision when creating the project management strategy.

Preferential Dependency

These dependencies typically rely on the team members, other stakeholders, and business procedures. When tasks are planned to adhere to defined standard practices, preferential dependencies develop. Even if you disregard the favorable dependencies in your tasks, the project will often still be competitive, but there will be some quality problems.

Cross-Team Dependency

This is quite frequent in large organizations. There are instances when numerous teams collaborate on a single, difficult project and rely on one another to finish it on schedule. To prevent excessive hours, effective project time management may be used.

Types of Task Dependency

The usual method for identifying dependencies makes advantage of the relationship between the start and finish requirements of the two elements under consideration. This leads to four possible dependence patterns −


Finish to Start is the most basic and typical of the four task dependence types. As a result, most projects will employ these task dependencies. According to the Finish to Start dependency, work must be completed before a successor task may be begun. In other words, one work must be completed before beginning another.


A finish-to-finish dependence demands the completion of both elements, with the first element completed before the second. Because work is accessible for the second element that doesn't require you to have finished the first element, you can work on both components simultaneously during this procedure. This frequently happens with tasks that have subtasks; if the subtasks are not finished, you cannot finish the parent task.


According to Start-to-Start, the successor task cannot be begun before the predecessor task. A first element must start in a start-to-start connection before a second one may follow. Both components may begin and run simultaneously. This frequently happens when two aspects need a lot of work and the second requires knowledge of the first. Again, this frequently applies to ongoing projects, but it is crucial to begin one before moving on to the next.


In a start-to-finish dependent relationship, one component must be finished before the next may be started. This frequently happens when there is a dependence involving the transfer of resources or information between the two parts, necessitating the commencement of work on the receiving element before the other element can be finished. This one is the most difficult and contentious of the four dependencies.


Understanding project dependencies and their types are important for better handling of projects. It allows you to make better project plans. Setting better estimates and becoming ready for time-constrained projects will be possible by organizing your project activities and comprehending their interdependencies. Additionally, you may determine the project deadline by understanding how each work in the project is connected to the others and calculating the length of time for each task.