Wednesday, August 8, 2018

After a few months, a new Scrum team's velocity should ____________.

Extraordinary claims require extraordinary evidence - Carl Sagan

As a Scrum Master or as Coach, I am sure you must have encountered a proverbial question:

"After a few months, a new Scrum team's velocity should ____________."

Does answer be “increase” or “remain constant” or something else?

Let’s explore the various aspects of this statement.

In a simplistic world, a team using the Scrum framework over a time period, its velocity keeps on increasing. There are claims that there is 400% to 1650% increase in productivity of the team in 10 sprints (  and Does this increase continue forever or a plateau reaches after a while?


Both of these scenarios have some underlying assumptions:
1.       The team’s composition remains stable over an extended period of time.
2.       The type of work team is doing remain similar over an extended period of time.
3.       The basis of estimation remains same over an extended period of time. A story estimated for three story points during the 1st month of the life cycle of the team is again estimated as three-story points during the 15th month of the life cycle.

There is one more assumption, with time team’s maturity increases. In practice, time and maturity are positively correlated but correlation factor is context specific. For accuracy purpose let’s keep X-axis of graphs as “maturity”.

Team’s maturity is multi-dimensional:
  • Embracing Agile and Scrum values backed by an implementation of processes, practices, and procedures embedded within the Agile principles
  • Ever increasing automation of repetitive technical tasks
  • Adoption of contemporary engineering practices
  • Emphasis on shift left approach
After taking account of the dimensions of the team’s maturity, a downward pressure on estimation becomes obvious.  This downward pressure arises due to familiarity with application, better understanding of business functions, and continuous learning of social structure within organization. A story estimated as five-story points may become three-pointer and then two-pointer after a while. This phenomenon reduces the slope of the line as the productivity of the team is increasing.

In this graph, velocity reaches a plateau after a while  due to continual downward pressure on estimation.

The team not only doing continuous improvements also making occasional innovations which result in quantum jumps in productivity, so in the velocity. This introduces steps like depiction in the graph.

With time, the effect of continuous improvements and innovations wear off due to slack in human nature and dynamic environment. This adds a downward pressure on the velocity graph; a plateau starts forming until a quantum jump due to innovation or significant accumulation of continuous improvement counter the downward pressure.

Over the time period, due to disruption in environment one or both of the assumptions (stable team, a similar type of work) break down. This resets the graph.