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--- what_is_the_basis_of_our_estimating_process [2019/01/07 10:54] – Added more discussion on relative sizing. hpsamios
+++ what_is_the_basis_of_our_estimating_process [2020/11/02 10:49] (current) – Cleaned up for readability hans
@@ Line 1: / Line 1: @@
 ====== What is the Basis of Our Estimating Process? ======
-The basis of this discussion is "Team based relative size estimates" or Story Point estimation and this list assumes that as a basis. This page is all about estimating User Stories (the requirement), not tasks associated with User Stories although a lot of the ideas could easily be carried onto the task estimation in hours. From there the assumptions are:
+The basis of the estimating process is "Team based relative size estimates" or "Story Point estimation" to estimate User Stories (the need). This means:
-  * We do relative size estimates (how big something is in relation to something else) estimates, not duration (how long something takes).
+  * We do relative size estimates (how big something is in relation to something else), not duration estimates (how long something takes).
-  * We use a team based approach to estimation such as planning poker or affinity (triangulation based) estimation
+  * We use a team based approach to estimation such as planning poker or affinity (or triangulation) estimation
-  * We have the people doing the work doing the estimates
+  * We have the people (in other words "the Team") doing the work doing the estimates
   * We use the modified Fibonacci sequence (1, 2, 3, 5, 8, 13, 20, 40, 100) for estimating
   * All data we collect can and should be used to understand what and how we are doing so that we can get better.
+  * The estimation process is refined. Estimations are revisited to see if they are accurate and precise enough.
-It is worth delving into the notion of a relative size estimate for a moment. Most traditional estimates are based on duration, and that leads to a whole bunch of problems (see [[what_is_the_purpose_of_estimation|What is the Purpose of Estimation?]] for more information). But it is worse than that. If you have two pieces of work to day, both of which you think will take about 20 hours to do, but the first piece of work is straight forward, while the second is in an area where there is a traditionally a lot of problems, should these items have the same estimate? No, you'll probably want to put some level of buffer in place to offer a more realistic estimate in the the case of the second piece of work. This is another reason to move away from pure time based estimates.
+===== Relative Estimates =====
-As [[http://www.agilejournal.com/articles/columns/column-articles/6458-lets-stop-the-wishful-thinking|Daryl Kulak]] says:
+>If two work items are the same size, should they always have the same estimate?
-<WRAP box>If a development team is equating some number of hours to a storypoint, it is missing the point (pun intended). Saying, “Thirty hours equals one point” is ridiculous. If you’re doing that, just use hours for goodness sake. You haven’t gained anything from storypoints except to be able to claim to be doing “agile.”</WRAP>
+It is worth delving into the notion of a relative size estimate for a moment. Most traditional estimates are based on duration ("it will take about 20 hours"), and that leads to a whole bunch of problems (see [[what_are_the_problems_with_estimation|What Are The Problems with Estimation?]] for more information). But it is worse than that. If you have two pieces of work to do, both of which you think will take about 20 hours to complete, but the first piece of work is straight forward, while the second is in an area where there is a traditionally a lot of problems, should these items have the same estimate? No, you'll probably want to put some level of buffer in place to offer a more realistic estimate for the second piece of work. This is another reason to move away from pure, absolute time based estimates.
-While the approach of using team based relative sized points is counter-intuitive at first, over time teams start to build up a a table of sizes in their heads:
+One thing that often confuses people who are used to traditional task based estimates is that the resultant estimate is a Team's view of how big this item is. When we say the estimate is a "3", we are really saying that the Team's view of this piece of work is that it is a "3". In particular, it is not a single Team member's view. When starting, many Teams fall into the trap of saying "There are design, implementation, and testing components of this piece of work. George will do the design so what do you think the estimate is for the design piece ... Jenny will implement, so what do you think the estimate for the implementation piece is ..." and then just sum up the results. In Agile the unit of execution is the "Team" and so the estimates indicate the size of work for the Team not the individuals on the Team. Sure the time to "design" and "implement" are part of that. But to deliver the value represented by the Story the Team might, for example, want to pair implementation and testing as they do the design to improve the design. Or the Team might find that testing might need an "all hands on deck" approach to assure quality. What we are estimating is the Team's ability to deliver value.
-{{ :screen_shot_2019-01-07_at_12.49.23.png?400 |}}
+>In Agile the unit of execution is the "Team" and so the estimates indicate the size of work for the Team not the individuals on the Team.
-As a starting point a team might say "lets say a day of work is a point". But what this really means is that particular item is also low in risk, and low in complexity.
+For more information on the basis of the process see [[https://www.youtube.com/watch?v=MrIZMuvjTws|Planning Poker for Estimates from Mike Cohn]]. Affinity mapping is based on [[facilitation_-_play_pass_or_move|Play, Pass, or Move]] approach.
-For more information on the basis of the process see [[https://www.youtube.com/watch?v=MrIZMuvjTws|Planning Poker for Estimates from Mike Cohn]]. And if you want to understand the scientific basis of this approach see [[Why Do We Use a Story Point and Relative Sizing to Estimate]].
+====== Want to Know More? ======
+  * [[where_did_this_estimation_approach_come_from|Where Did This Estimation Approach Come From?]]
 {{tag>Team Estimates Forecast FAQ Points EstimationApproach}}