Wednesday, September 26, 2018

Relative Estimation – Epics & Features and Reference Scale

Estimation in Agile world is relative at each level of requirements. Having an enterprise wide reference scale is a journey. To start in journey lets’ start.
First Step
1.     To estimate Epics, use ordering protocol method (arranging big to small in an ordered list):
  • Enormous (E)
  • Intermediate (I)
  • Humble (H) 

To estimate epics Epic owners, representatives from architect community, representatives from system community, and representatives from PM & PO come together and classify them as Enormous, Intermediate, and Humble.
2.     Features are estimated on a relative scale of T-shirt sizing:
  • Extra Large (XL)
  • Large (L)
  • Medium (M)
  • Small (S)
  • Extra Small (XS)

To estimate features PMs, POs, representatives from Architect community, representatives from System community, and representatives from Development community come together and classify them as XL, L, M, S, and XS.

3.     Stories are estimated using Fibonacci series on relative scale by Development teams.

In mean time Story Mapping and Refinement efforts are underway to gain better understanding around functionality and dependencies.

Next Step
Over the time, the organization builds a reference map to have a range based correlation of all three levels of requirements.

To build these reference maps representative epics, features, and stories are contributed to reference scale by Epic owners, PMs/POs, and DevTeams. To keep the reference scale up to date:

  • Epics older than 6 months (or may be one year);
  • Features older than 3 months (or may be 6 months); and
  • Stories older than one PI (may be two PI)
should be dropped out from the reference scale. 

This range based maps may look something like:

In this scale, the range of uncertainty keeps on narrow down from Epic to Story but increases as size increases.

You can also view the reference scale on a common denominator of Story Points.

Few important points to be taken into consideration:

  • Purposefully, different scales are used for each level in requirement hierarchy.
  • To avoid HiPPO (Highest Paid Person’s Opinion) effect, people with high sounding titles must speak in last or not at all.
In this estimation process, the emphasis is on estimation not on team capacity and cost of realization of a specific Epic/Feature/Epic.