Project Dependencies – Hard logic, Soft logic

Project Dependencies are what it literally means. There are 4 types of project dependencies – Mandatory dependency or Hard logic, Discretionary dependency or soft logic, External Dependency, Internal Dependency. This concept is not a difficult one, if not easy. Before going to the different types and attributes of dependencies, let’s first understand what a dependency is.

What is Project Dependency?

In simple terms, Dependency means “Logical relationship”. In the Project Management world, Dependency is a logical relationship between two activities, or between an activity and a milestone.

What is a Dependency Attribute?

In Project Management, a Dependency Attribute is the characteristic of a dependency.

There are 4 dependency attributes: 1) Mandatory 2) Discretionary 3) External 4) Internal.

Based on these 4 attributes, there are 4 types of dependencies

1. Mandatory dependencies
2. Discretionary dependencies
3. External Dependencies
4. Internal Dependencies

Further, Two attributes can be applicable at the same time resulting in 4 more dependencies

1. Mandatory External Dependencies
2. Mandatory Internal Dependencies
3. Discretionary External Dependencies
4. Discretionary Internal Dependencies

Now, let us see the different types of dependencies based on the types of dependencies.

4 Basic Types of Project Dependencies

Mandatory Dependencies or HARD LOGIC

• These are legally or contractually required or inherent in the nature of work.
• They often involve physical limitations (eg: In a construction project, you can’t erect the walls with out laying the foundation first.).
• They are referred to as Hard logic or Hard dependencies.

Discretionary Dependencies or SOFT LOGIC

• These dependencies are established based on the knowledge of best practices, even though there are many other possible sequences of doing things.
• They are referred to as Soft logic or Preferential logic or preferred logic.
• You can modify discretionary dependencies if necessary.

External Dependencies

• These involve dependency or logical relation between the project and a party outside the project. 
• These dependencies are usually outside the Project Team’s control. 

Internal Dependencies

• These involve a sequential relationship between different activities of a single project. 
• These dependencies are usually inside the project Team’s control. 

Who identifies the dependencies?

Mandatory & Discretionary dependencies are identified by — Project Team

External & Internal dependencies are identified by — Project Management Team