Some companies define project interdependencies as “Hard” or “Soft” based on a type of constraint in their scheduling tool. In other situations, project interdependencies indicate a level of risk as probability, impact or risk exposure. Some project management practitioners define Hard vs Soft based on a level of contingency in a provider or receiver schedules. This inconsistency in project interdependency definitions sometimes creates real confusion amongst project managers.

It is quite common to have a different management approach to Soft and Hard dependencies as they  have different risk levels. With such definitions, it is easy to miss a point when a dependency changes it’s type from Soft to Hard.  And since a Hard project interdependency often sits on a critical path, this situation turns into an issue that leads to the whole project delay and sometimes even generates “a domino effect” across the entire Program or Portfolio.

A dependency type is supposed to be a stable characteristic, which supports Project managers in their agreement on whether their projects are dependant or not.

SDPD Interdependency Management Framework defines three types of dependencies: Hard, Soft and  Virtual based on the nature of dependency. These types are stable, mutually exclusive and support project managers in dependency identification and risk analsis. Also, a PMO could develop appropriate solutions to manage each type of dependency.

Hard Dependencies: A -> B
Project A (Provider) is providing a deliverable to Project B (Receiver). Project B (Receiver) would not be able to deliver all its capabilities successfully if Project A (Provider) delays or does not provide a required deliverable to Project B (Receiver) within agreed time and quality.

Soft Dependency: A~>B
Project B (Receiver) dependant on Project A (Provider), but Project B (Receiver) would be able to deliver project capabilities even in a case when Project A (Provider) is delayed or cancelled.

Virtual Dependency: (A,B,C)
A virtual dependency is a dependency when different projects operate in the same environment and impacting each other. A virtual dependency doesn’t have Provider and Receiver project.

Often, but not always, Hard dependency is associated with a project risk and Soft dependency relates to opportunity. Virtual dependency could be a risk or an opportunity and is not always associated with an event or a deliverable. Often it requires visibility of project activities and is less stable.


• Project A provides a design to project B and project B is not able to progress without the design. 

• Project A delivers a new PPM tool, but project B could use old PPM if the new system is not available on time.

• Two projects need the same critical resource during the same period of time
• Three projects need the same test environment during the same period of time 
• Two projects deliver training to the same group of people during the same period of time
• Benefits could only be realised when two outputs delivered by different projects.

SDPD Interdependency Management Framework also includes some other critical dependency characteristics, methods and tools which support Programs and Portfolio delivery optimisation.

Alex Lyaschenko

PMO | Portfolio Planning & Delivery | PMP | P3O Practitioner | AgilePM Practitioner | Six Sigma