Blog articles

Hard or Soft Interfaces?

One of the common debates amongst interface management professionals is about the difference between hard and soft interfaces, and how to handle them. Or between tangible and intangible. Below are some of the terms displayed at the last interface management conference.

The terms brought up related to the type of interface

Hard interfaces are tangible - they are the physical, technical, engineering interfaces between two pieces of equipment, which can be clearly defined, discussed and agreed upon.
Interface issues between different contractors - using interface registers - are almost always related to hard interfaces.

Soft interfaces are intangible - they are not physical, and do not relate to any specific interface between two pieces of equipment.
They might relate to some kind of organisational interface - between two teams, companies or other stakeholder groups.
Is this the business of the interface manager? Well, yes - especially as badly-defined or weak-functioning soft interfaces may make it difficult or impossible for the people working with the physical, technical interfaces to do their job.

Dealing with these soft, intangible interfaces is just as important as setting up the structures and systems for dealing with hard interfaces, but needs to be handled in a different way, and preferably earlier in the project.

At the 3rd Interface Management conference (in London, October 2016) delegates were invited to write specific interface terms on paper and put them on the wall. We ended up with 48 different terms. This article is the second in a series that discusses the themes that came out of this exercise.
This article was written by John Thropp and first published in February 2019.