How to estimate tasks

A presentation on the agile method of coming up with estimations

Transcript

1. How to estimate tasks Moringa Devshop Chencha Jacob
2. Task Estimate An approximation of how long a task will take should be based on previous work. Made by the development team Not negotiable
3. Target A deadline to be met. The target is usually set externally to the development team. The date is usually not negotiable.
4. Commitment Real enforced work to which the development team must meet. Usually enforced by contract. Negotiable
5. Story points A story point is an arbitrarily unitless measure of effort. Story points are a useful tool to compute estimates for the team. What makes them so powerful is that they leverage on the inherent competency of human beings to make relative estimates. Story points are all relative.
6. How to do story points 1. Chose a relatively simple and easy to estimate story from the backlog 2. Assign that story a number. This is known as the story point 3. Move on to the next story 4. If it seems about the same size assign it the same number if it seems about double assign it as so.
7. The golden ratio While using arbitrary points works well. An even better mapping exists. The Fibonacci sequence is a series of numbers where a number is found by adding up the two numbers before it. Any two successive fibonacci numbers have a ratio that fits really close with the golden ratio.
8. History of the golden ratio Phidias (490–430 BC) made the Parthenon statues that seem to embody the golden ratio. Luca Pacioli (1445–1517) defines the golden ratio as the "divine proportion" in his Divina Proportione. Johannes Kepler (1571–1630) describes the golden ratio as a "precious jewel": "Geometry has two great treasures: one is the Theorem of Pythagoras, and the other the division of a line into extreme and mean ratio; the first we may compare to a measure of gold, the second we may name a precious jewel." These two treasures are combined in the Kepler triangle. Charles Bonnet (1720–1793) points out that in the spiral phyllotaxis of plants going clockwise and counter-clockwise were frequently two successive Fibonacci series. Roger Penrose (b. 1931) discovered in 1974 the Penrose tiling, a pattern that is related to the golden ratio both in the ratio of areas of its two rhombic tiles and in their relative frequency within the pattern. This in turn led to new discoveries about quasicrystals. Chencha Jacob. (ca 2016) Talks about the Golden ratio in Software Engineering
9. Fibonacci and story points Sample fibonacci sequence 1,1,2,3,5,8,13, … Steps: 1. Assign story point of 1 to the easiest user story 2. Assign 2 to any story that is bigger than that one but seems less than 3 times 3. Assign 5 to one that seems more than 3 times but less than 8 times 4. Continue so forth assigning to the higher number
10. The catch It will be tempting to directly map the story points to time units. Avoid this temptation as you would the plague! Story points are ratio measurements which means they can be added, subtracted, multiplied and divided in a way that makes sense. However they have no direct mapping to cardinal time units. For this mapping to happen another measurement must be established.
11. Velocity Velocity = Story points done/length of the sprint Each development team has a unique velocity. Once velocity is established the story points can now be converted to the number of sprints and an estimate computed. Estimate = Total story points / Velocity Commitment = Estimate + Risk adjustment