The Difference Betwean Roadmaps and Gantt Charts
My colleagues and I at Easy Agile often get asked “What‘s the difference between a roadmap and a gantt chart?”. Folks must be quizzing us!
Do you know who created the Gantt chart? And what it was designed for? We’ll investigate that in a bit, but first… Gantt charts for agile teams. What?!?!
Agile is not about task dependency and critical path management — it’s about flexibility and temporary dependency. - Michael Dubakov
And that’s what a Gantt chart is exactly for — task dependency and critical path management. If I’m building a data centre then I definitely have task dependency to manage, as I can’t put in electrical conduit before the fire sprinkler piping has been completed.
Building a physical object like a bridge is one of those areas where Gantt charts are common and make sense.
And Gantt charts are perfectly ok. It’s just not agile.
What are Gantt charts?
While you may be forgiven for thinking Gantt charts look similar to a roadmap, at their heart they serve different purposes and audiences.
Gantt charts assume that work will be completed in a linear fashion. Further, tasks often have that liner delivery as they are directly dependent upon one another. And any modification to the schedule is treated as a negative, something which should be actively managed out.
This in and of itself goes against the very principles of what ‘agile’ is!
The development of agile methodology was out of a need to address common inefficiencies of more traditional project management methodologies in the software development process, such as Waterfall.
If we look at what makes a team agile we often think about traits such as:
Early and ongoing delivery
Why does an agile team need a roadmap?
A roadmap looks beyond what you’re doing now. It explores not where you’ll be soon, but where you could be in a year. - Steve Johnson
Roadmaps assist agile teams in defining the big chunks of work they want to do and when. It is a tool to communicate with the team, with customers, and with stakeholders throughout the business.
A roadmap isn’t fixed. Dependencies may exist, yet there will be loose coupling. Learning and adaptability are favoured over rigidity.
Roadmaps allow agile teams to have a sense of the journey they are taking their customers on over the next 3–6 or even 12 months. By understanding this customer journey, teams are better able to understand the evolution of their product based on desired customer outcomes.
For more on the practice of roadmapping see: What is a roadmap? How does it aid agile team effectiveness?
So, who did create the Gantt chart anyway? And why?
Henry Lawrence Gantt created the chart way back in the 1910's! That’s why it is always capitalized, as it’s named after him. Henry created it to provide a graphic schedule for the planning and controlling of work, and recording progress towards stages of a project.
Gantt charts were employed on major infrastructure projects including the Hoover Dam and Interstate highway system. Fun fact, early Gantt charts used “production cards” for assigning work to each worker and recording how much was completed each day.