05 Process Milestones, Estimation, Planning

  • How to develop software?

    • Discuss the software that needs to be written
    • Write some code
    • Test the code to identify the defects
    • Debug to find causes of defects
    • Fix the defects

  • Improving Process Reliability:

    • Write down all requirements and require approval for all changes to requirements.
    • Use version control and code reviews.
    • Track all work items
      • Break down development into smaller tasks
      • Write down and monitor all reported bugs
      • Hold regular, frequent status meetings
    • Plan and conduct quality assurance
    • Employ a DevOps framework to push code between developers and operations
    • ![[Screen Shot 2024-10-07 at 05.30.13.png]]
    • Hypothesis: Process increases flexibility and efficiency
    • Ideal Curve: Upfront investment for later greater returns

  • Cost of Defects Based on Creation and Correction Phases:

    • Defects created earlier in the project (during requirements or design phases) are much cheaper to fix than those created later (during construction or maintenance).
    • The cost to correct defects grows exponentially the later they are discovered and addressed.

  • Waterfall Model: This slide introduces the Waterfall model, which was the original software process. The steps include:

    • Requirements
    • Design
    • Implementation
    • Verification
    • Maintenance
    • Each phase flows into the next, similar to a waterfall, where each stage must be completed before the next begins.

  • Lean Production and Toyota Production System (TPS):

    • Toyota Production System (1940s) introduced lean production concepts.
    • The focus is on building only what is needed, using a "pull" system (Kanban) to avoid overproduction.
    • The system emphasizes fixing problems early, empowering workers to take ownership, and continuous improvement (kaizen).

  • From TPS to Agile & Scrum: Modern processes focus on flexibility and iterative development, breaking down tasks into sprints with frequent feedback loops.

  • Elements of Scrum: ![[Screen Shot 2024-10-07 at 06.06.53.png]]

    • Backlogs
      • Product Backlog: List of all features needed for the product.
      • Sprint Backlog: Features/tasks to be completed in the current sprint, broken down into smaller, manageable tasks (fine-grained, estimated, assigned to members).
      • User stories are commonly used to describe tasks.
    • Kanban Boards (Project Board in GitHub)
      • Visual representation of the workflow, often divided into columns like "Backlog," "In Progress," and "Done."
      • Helps teams track progress and identify bottlenecks in the process.
    • Scrum Meetings
      • Sprint Planning: The team decides what to tackle in the upcoming sprint.
      • Daily Scrum: A quick meeting to address what was done, what’s next, and any obstacles.
      • Sprint Retrospective: Reviews the process and suggests improvements.
      • Sprint Review: Focuses on reviewing the product.

  • User Stories:

    • Describes features from a user’s perspective: "As a [role], I want [function], so that [value]."
    • User stories - INVEST framework
      • Independent
        • Schedule in any order.
        • Not always possible
      • Negotiable
        • Details to be negotiated during development
        • Good Story captures the essence, not the details
      • Valuable
        • This story needs to have value to someone (hopefully the customer)
      • Estimable
        • Helps keep the size small
        • It should provide enough details to estimate the amount of effort needed
      • Small
        • Fit on 3x5 card
        • At most two person-weeks of work (one sprint)
        • Too big == unable to estimate
      • Testable
        • Ensures understanding of task
        • We know when we can mark task “Done”
        • Unable to test == do not understand
Principle Violating Story Why it Violates Fixed Version
Independent As a user, I want to receive notifications for events after the event calendar is set up, so I don’t miss any events. This story depends on the development of the event calendar, making it not independent. It cannot be worked on until the calendar feature is completed. As a user, I want to receive notifications for events I’ve shown interest in, so I don’t miss them.
Negotiable As a user, I want a button that sends email notifications for every event 30 minutes before the start time, and it should include the event name, location, and duration. The story is too specific and doesn’t allow room for negotiation. The development team has no flexibility to discuss other options. As a user, I want to receive a reminder about upcoming events, so I can be notified before they begin.
Valuable As an admin, I want to export user data to a CSV file. This story lacks clarity about why the feature is valuable to the user. It focuses on a technical feature without explaining its purpose. As an admin, I want to export user data to a CSV file, so I can analyze user activity trends and make data-driven decisions.
Estimable As a user, I want the app to be fast and reliable at all times, so I can have a smooth experience. The story is too vague and broad. It’s impossible to estimate the effort required without more specific criteria or measurable goals. As a user, I want the app to load the main dashboard in under 2 seconds, so I can access the information quickly.
Small As a user, I want to manage my profile, upload a profile picture, and update my privacy settings from the settings page. The story is too large and covers multiple features. This would be difficult to complete in one sprint and needs to be broken down. As a user, I want to update my privacy settings, so I can control who sees my information.
Testable As a user, I want the app to work well on all devices. The story is too vague and doesn't have clear acceptance criteria, making it difficult to test. As a user, I want the app’s homepage to display correctly on mobile devices, so I can easily navigate it on my phone.

  • Improving Time Estimates

    • Prevent conformity bias.
    • Consider past comparable experiences to base an estimate on.
    • Determine how much design is needed for each task.
    • Break tasks down into smaller tasks and estimate those.

  • Milestones and deliverables make progress observable

    • Milestone: clear end point of a (sub)tasks
      • For project manager
      • Reports, prototypes, completed subprojects
      • "80% done" is not a suitable milestone
    • Deliverable: Result for customer
      • Similar to milestones, but for customers
      • Reports, prototypes, completed subsystems

  • Time Estimation and Milestones:

    • Time estimation is difficult but necessary for planning.
    • Break tasks into smaller parts to improve estimation accuracy.
    • Milestones mark clear endpoints in a project and make progress measurable.