A Complete Guide to Dependencies in Project Management

Emiliano Pardo Saguier July 15, 2022
- 6 min read

Dependencies in project management address issues many consider part of the A-B-Cs of successful project management

Nothing happens in a vacuum. If you were building a house, you’d start with a foundation. This is how dependencies operate, regardless of your industry. This article will help you categorize each dependency and get things off the ground. 

Let’s dive right in.

What are project dependencies?

Every successful project has to go through the planning stages first. This requires restricting a clear line to the finish, a sequence of events that has to take place for things to get from where they are to where they need to be. 

You have to find out what task is a dependency of the other. If task B requires you to finish task A, task B depends on task A. Moreover, dependencies themselves are dependent on other factors and ideas. These are: 


Project constraints are deeply linked to dependencies. They are restrictions or boundaries, lines the project manager has to color inside. 

We can detect three main constraints that define every project’s critical path: 

  1. Cost 
  2. Project scope
  3. Time 

They’re self-explanatory, so we don’t have to delve too deep. But, for instance, let’s consider costs as a limiting factor. If you can only hire a single developer for a project, then the tasks that require software development will depend on each other. 

Lead and lag 

No, we’re not talking about a match of competitive gaming. Lead and lag are two concepts that merit their different explanations. 

Lead is an idea that applies to “start for finish” dependencies, or the fact that task B cannot start until task A is finished. Thus, the idea is to take less time with task B to accelerate the time it takes to get things done. Project managers use lead times to reduce the overall time required to finish a project successfully. 

Lag, on the other hand, is not related to any sort of relationship between project dependencies. Instead, it refers to the time delay between tasks when no resources are used. While you ideally want to minimize lag times to zero, sometimes it’s required and simply a fact of life. 

Critical path

This sequence of events leads from where a project begins to the end zone. As such, you can’t allow substantial delays in any task in a critical path, or the whole project will suffer from it. The only way to get around this is by completing another urgent task beforehand and saving up time preemptively. 

How many dependency types are there in project management? 

Internal or external factors mandate the significant categories of project dependencies. Here are the ones to look out for: 

1. Logical dependencies 

These are causal dependencies, meaning they’re an inherent part of every project type, and cannot be avoided. Any task that relies logically on a preceding job will require input from the previous one to be completed. Hence, you cannot get started on task B until you’re done with task A. 

In other words, tasks with a logical dependency on a preceding one can’t be run in parallel. 

2. Preferential dependencies 

These dependencies rely on team members, other stakeholders, or other industrial practices. Preferential dependencies come into play when your project must meet standard practices (such as ITIL, for example).

While most preferential dependencies are not mission-critical, your project’s overall quality may suffer if you don’t follow them. Ignore them at your peril. 

3. Resource dependencies

This dependency type refers to limited shared resources. If two parts of the project require the same aid for completion, they will become dependent on each other. 

4. External dependencies

Regardless of how well we plan things, some factors are beyond our control. As some tasks depend on project factors, it’s up to project managers to plan, even creating backup plans. While you don’t have to be a strategic mastermind, you do have to account for things like supplier delays and the like. 

Contingency plans keep the doctor at bay, in other words. And those who don’t plan? Well, they’ll probably see lag times go through the roof and have significant issues with the completion of their projects.

5. Cross-team dependencies 

It is more of a factor for large organizations. In these cases, multiple teams may work on a single complex task and rely on each other to get things done. 

In a previous article, we talked about why having a project management plan when juggling multiple teams is even more critical: 

“A project management plan is a document or group delineating the steps teams will follow to complete a project. It is used as a guideline to manage the project, following its intended scope and ensuring its goals are met. The idea behind a project plan is to act as a roadmap that will show all the steps and resources that must be considered when trying to complete a project on time and within its budget constraints. 

It’s crucial to understand that project management plans contain key information for all stakeholders to be informed at all times. This means milestones, assignments, deadlines, and more. More often than not, project management plans are represented in a Gantt chart to ensure that everybody is clued in at all times.”

How to handle dependencies

There’s no surefire way to tackle dependencies and not one that would work on every type of project. Yet, some common-sense ways to deal with dependencies are: 

  • Talk to your stakeholders. As a project manager, you need to get everybody on the same page and communicate every step of the way. And the main thing to do is to make everybody keenly aware of dependencies that might affect their job. 

  • Visualizing is another essential part of the project management plan. Having things charted out visually is a great way to let everyone know how each dependency connects to others, especially those on the critical path. A Gantt chart software exactly helps you do that.

  • Create a risk log. It’s not just a matter of knowing about each dependency — now, you also have to be mindful of how each could affect the project’s outcome if it’s not dealt with correctly or on time. External dependencies, for example, can wreak havoc on your project if they’re not addressed beforehand. Additionally, constraints also have risks of their own, so that ⅗ o damage mitigation will hinge on prevention practices. 

  • Contingency plans. You can’t win them all, and sometimes you must set goals for when the house catches fire. You’ll ensure that the project will be successful. Risk management is going to help you. 

Key takeaways

If you let them, dependencies can quickly get out of hand and derail an entire project. But, if you stay on top of things and keep each dependence accounted for, they’re just a regular fact of life that’s part of every project. 

Being a project manager, though, will require that you keep things mapped out, plan, and can think proactively, both in a way that avoids risks and in one that can deal with them when they appear. 

If you do, there’s no reason for you not to steer any project towards success, regardless of its scope. 

Frequently Asked Questions

What are dependencies? 

Dependencies, in project management, are about demarcating a clear line from where a project starts to where it ends. Then, you can determine which tasks depend upon the completion of others before you can start working on them. 

What other concepts are linked to dependencies? 

There are concepts that dependencies themselves depend upon. Things like constraints (cost, project scope, time), lead and flag, and critical-path concepts can help you outline the boundaries of your project dependencies. 

How many types of dependencies are there?

There are five types of dependencies:

  1. Logical
  2. Preferential
  3. Resource
  4. External
  5. Cross-team

Read other articles like this : Project Management

Evaluate InvGate as Your ITSM Solution

30-day free trial - No credit card needed