Exercise 6: Planning

Question 1

What are the goals of planning?

Answer 1

• Determine project duration
• Get accurate estimates
• Reduce the project time
  
  • Find slack time
  • Parallelize tasks
• Stay in the estimated project time
  
  • Find critical activities

Question 2

Purpose of dependency diagrams

Answer 2

• 1. Compute the project duration
• 2. Determine activities that are critical to ensure a timely delivery
• 3. Draw the dependency diagram
• 4. Analyze the diagram
     * Find ways to shorten the project duration
     * Find ways to parallelize activities
     * Analyze dependencies
• Two techniques are used
  
  • Forward pass (determine critical path)
  • Backward pass (determine slack time).

Question 3

Adjusting the estimation: 3-Point Method

Answer 3

• Disadvantage of PERT estimation: only one estimate per activity.
• Likelihood of being correct?!
  
  • -> Cone of Uncertainty: estimation results can deviate from actual effort by a factor of 4.
• Estimation with PERT can be adjusted: use multiple estimates for each activity and calculate average and deviation.
• Estimate the best case, the likely case and the worst case.
• Effort for an activity i is calculated with the weighted average of the three estimates:
  Ai = bci + 4*lci+wci / 6
• The standard deviation of estimation for activity i is: si = wci - bci / 6
• Effort of the whole project: Sum of Ai over N

Question 4

Estimation in Scrum: Planning Poker

Answer 4

• Estimation technique for complexity of user stories
• Entire development team participates in estimation
• Points are not equivalent to time units
• Points can be used to analyze team metrics

Question 5

Planning Poker: Rules

Answer 5

1. Each member receives a set of cards containing modified Fibonacci numbers
   0 1⁄2 1 2 3 5 8 13 20 40 100
2. Scrum Master selects and reads a user story to discuss and defines the acceptance criteria
3. Team discusses the complexity of the user story
4. Each team member considers how many points the task should receive
5. All team member’s suggestions are revealed simultaneously
6. If estimates match –> done. Else, repeat steps 3-5 at most 2 times.

Question 6

Planning Poker: Pros and Cons

Answer 6

• Pros
  
  • Team of experts leads to more accurate estimations than in traditional methods
  • Distribution of workload according to skill: Developers who estimate few points are good candidates to implement the user story
  • Developers having a role in what user stories they are responsible for in a sprint lead to a higher work motivation
• Cons
  
  • Many people in a group may lead to long discussion
  • Lazy developers want to overestimate tasks, in order to have less user stories assigned to them in a sprint
  • People tend to want to average the amount of points, which limits the discussion and may not represent the actual difficulty of the task

Question 7

Tips for Planning Poker

Answer 7

• Keep discussions productive: Set a limited amount of time for each user story discussion. This helps teams learn to estimate more rapidly within agile planning.
• Break out into smaller sessions: Playing Planning Poker with a sub-set of the team is a good option if the number of user stories is too big.
• Choose the right time to play: Consider playing it several times; once at the kick off, and once before each Sprint.
• Write down the reason for the awarded points: If a user story receives too many points, make sure to note what were the Acceptance Criteria that led to that estimation.
• Consider the level of uncertainty: Does the implementation of this user story depend on too many unknown factors? If yes, maybe award more points.