Agile software development has teams estimate the effort to deliver requests from the product owner. The estimates are done in points (in order to abstract away from hours – as estimates have plenty of variation in how long they will really take). Then the teams capacity (velocity) is determined based on looking at how many points they complete in a “sprint” (a set length, often 2 weeks). Then the product owner can prioritize all of the requests with an understanding of how much effort each is estimated to take and the historical capacity of the development team.
I think it is good to add point estimates to bugs. It may well impact how bugs are prioritized – if it is known to be simple a program manager may say, yes I want these 6 first then… If then know the first 2 are likely to take a bunch of time, they may think, ok, I am not going to get these 4 for awhile… They might just accept that, or may wish to shift more hours to bug fixes this sprint. Or they might say well if it is that big an issue maybe we could do x instead…
In practice I rarely has us estimate emergent bugs we are going to fix in the current sprint, but we do it for bugs that are in the backlog. I sometimes will have us estimate a current bug if I think it is may take significant time – to help determine what we really want to and what the impact may be on the teams output for the sprint. We do not have many emergent significant bugs so it isn’t much of an issue for us.
We do have more difficulty accurately estimating bugs, compared to new stories, but we still provide actionable estimates (they are not perfect, but are usable).
We use agile software development principles at work and they have been a great help in letting us be much more effective than we had been previously. The discussion of priorities and delivery expectations are much improved by such methods I believe. And unrealistic expectations can be reduced. For various reason, without adopting some form of agile/lean… software development methods the common pattern I see is software developers being frustrated by unrealistic expectation of their customers (project managers…) being frustrated by failure to communicate what it is reasonable to expect and status updates. A big part of this is the failure to acknowledge variation (and the related difficulty in estimation). Agile/Kanban… are systems that take the variation into account, and therefore the variation is dealt with as natural instead of leading to bad outcomes for developers and their customers.