Backlog containing mostly bugs

Last post 02:17 pm February 18, 2014
by Joshua Partogi
6 replies
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09:05 am February 17, 2014

Hello,

My team has to work with a product backlog that contains lot of bugs most of them legacy but also bugs that are coming from late testing stages (bugs identified after one month or so after feature complete). We were advised to not provide story points for these bugs as the story points are reserved for new features. However, if do not provide story points it will be difficult for us to estimate a velocity.

Which is the best way to handle the estimations in this case? Currently, for a bug we are estimating only the number of hours that are required to fix it. We are using Rally as Agile tool so for each story we can have both story points and hours.

Thanks,

Mircea

10:21 am February 17, 2014

> We were advised to not provide story points for these bugs as the story points are reserved for new features

Who advised you of this? In Scrum the Development Team is responsible for the estimation of its own work. If these bugs represent work that the team is expected to do, then they must be in a position to estimate it, and no-one has the authority to forbid the team from doing so.

> Currently, for a bug we are estimating only the number of hours that are required to fix it.

For bugs that are raised in-sprint a defect can be raised as a task against the story. It's reasonable to estimate tasks in hours.

For bugs that are raised out-of-sprint (i.e. against work that has already been accepted as Done), the defects should be triaged into the Product Backlog and ordered, assuming they do not represent P-Level incidents that require immediate attention. They shoud be estimated the same way as other PBI's (e.g. by story points).

11:12 am February 17, 2014

Thanks Ian! Very clear answer.

12:13 pm February 17, 2014

Hi Mircea,

As a Scrum Coach, I get asked these questions all the time.

Note that in the post below, if it ends up on the PBL then you would assign whatever units you use to estimate PBI"s, but if on SBL, then whatever units you estimate for items on the Sprint Backlog.

http://ScrumCrazy.com/bugs

Note that the above approach is just one approach. Scrum simply dictates that PBI's and items on the Sprint Backlogs have some way of being estimated. It is up to the Scrum Team to decide how that is done.

05:43 am February 18, 2014

# Task Items can be sized in Ideal Hours.
# Backlog Items or User Stories can be sized in (Story) Points.

Based on how The Development Team is looking at a particular bug, it could end up being an Item or a Task. This selection will govern the unit of size.

05:50 am February 18, 2014

Task Items = Task in above post!

02:17 pm February 18, 2014

Hi Mircea,

Scrum doesn't differentiate between Bugs and User Story, both are considered as Product Backlog Items. With that rules applied that means I can also assign points to Bugs?