AGILE RE

How is RE done in agile processes?

Lecture 15

Material in this lecture based on: https://www.ireb.org/content/downloads/34-cpre-re-agile-primer-syllabus/ireb_cpre_re%40agileprimersyllabusandstudyguide_en_v1.3.pdf

Announcements

• HW6 peer eval (optional) closes tonight 11:59pm
• No discussion Monday
• HW7 due Tuesday 11:59pm
• Last lecture is Tuesday (no lecture Thursday)
• Please maintain an attitude of respect for all people, any behavior otherwise will not be tolerated

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Canvas Quiz

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Lecture 15: Lecture 14 Review

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Last Time (I) – Did we specify the right thing?

• Requirements validation/QA is a major concern in view of error diversity, frequency, criticality, cost
• Requirements validation should check the [near] final draft of the requirements document for conflicts, omissions, and deviations from standards (among other errors)

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Last Time (II) – Did we specify the right thing?

• Requirements validation techniques:
• Requirements reviews/inspections
• More effective if using well-planned process & specific checklists
• Requirement prototyping
• Testing a prototype that has been developed during elicitation
• Model validation
• Paraphrasing (into natural language)
• Requirements testing
• Designing tests for requirements can reveal problems with the requirements
• Formal checking
• Powerful, automated, but requires formal specs

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Today’s Lecture – How is RE done in agile processes?

• Agile motivation and mindset
• Fundamentals of agile RE
• Agile RE work products
• Agile RE techniques

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Today’s Lecture – How is RE done in agile processes?

• Agile motivation and mindset
• Fundamentals of agile RE
• Agile RE work products
• Agile RE techniques

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Today’s Lecture

• Agile

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Some Agile Principles

• Welcome change in requirements
• Face-to-face conversation is the best way to convey information
• Working software is the primary measure of progress; documentation is just a means to an end
• Business people and developers work together daily throughout the project
• The best architectures, requirements, and designs emerge from self-organizing teams

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Models, plans, and documentation are important and have their value, but exist only to support the development of working software.

Today’s Lecture – How is RE done in agile processes?

• Agile motivation and mindset
• Fundamentals of agile RE
• Agile RE work products
• Agile RE techniques

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Requirements in agile development

No classic requirements specification document (unless mandated by regulators)

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Various work products that ...

• specify requirements: vision, user stories, epics, use cases, models...
• have requirements-related content: prototypes, mockups, storyboards, roadmap, early product versions (e.g., MVP)

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Value-driven creation of work products

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Source: https://www.pm-partners.com.au/insights/the-agile-journey-a-scrum-overview/

Agile Requirements - Product Backlog

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Requirements Engineer (RE) vs. Product Owner (PO)

• RE core activities:
• Elicitation
• Documentation
• Validation
• Negotiation
• Management

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• PO core activities:
• Ensure the team delivers constant business value
• Manage all stakeholders
• Continuously supply the team with items from the backlog having the greatest business value

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Both REs and POs perform the same basic tasks, but the notations and tools are usually less formal in agile processes.

RE as a continuous process

• In agile, RE is less a distinct development phase and more an iterative, ongoing activity
• High-priority requirements should be refined/detailed enough to be ready for implementation
• Lower priority requirements will only be refined once the urgent ones are complete
• Upfront RE activities are still required
• e.g., defining vision/goals, analyzing stakeholders, establishing project scope

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Value-driven development

• Agile methods strive to continuously deliver business value to the end user
• Value expressed in:
• Financial terms
• Increased market share
• Customer satisfaction
• …
• In order to determine which requirements lead to the optimal value, agile methods often strive for MVPs

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Simplicity as an essential concept

• In a complex world, simplicity is a way to embrace complexity by:
• Creating a simple (and potentially incomplete) response to a problem, thus creating a small increment of value
• MVP (Minimum Viable Product)
• The smallest product that can create an end user experience and provide feedback to the team

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Inspect and adapt

Agile methods emphasize the importance of frequent and fast feedback

• about the team
• about the development process
• about the product

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Assumptions for Successful Agility

• All stakeholder roles are reducible to one single role
• “User/customer” that is on-site
• Project small enough for one small co-located development team
• Functionality can be provided quickly, consistently, incrementally from essential to less important
• Non-functional aspects, environment assumptions, objectives, alternative options, risks may receive little attention
• Little documentation required for work coordination and maintenance; requirements precision not required; verification before coding is less important than early release
• Requirements changes are not likely to require major code refactoring

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Source: modified from van Lamsweerde, 2009

When to use Agile?

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Why not just do agile and forget RE?

• Yes, the majority of projects nowadays are agile
• But there are still those that follow traditional processes, and for most of those, doing requirements engineering right is often a life or death matter!
• Even with agile, you still need a good understanding of requirements

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More/less agile is achievable by less/more weight in RE activities

Canvas Quiz

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Lecture 15: Agile RE Fundamentals

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Today’s Lecture – How is RE done in agile processes?

• Agile motivation and mindset
• Fundamentals of agile RE
• Agile RE work products
• Agile RE techniques

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Documenting agile requirements

• General guideline: do things only if they add value
• A simple approach:
• Writing user stories (using a standard template; see lecture 8)
• Adding detail with acceptance criteria
• Structuring stories with epics and features
• Organizing stories in a product backlog

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• Implementation-oriented approach
• Does not scale well to settings with > 1 agile team

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Agile work products (1)

• Product backlog
• Ordered list of everything (functional) that might be needed in the product
• User stories
• Acceptance criteria
• Index cards, sticky notes, captured in a SW tool
• Product vision
• Defines the goals and provides the definition of success
• Context model
• Defines context in which the product will operate
• Used to clarify scope, external interfaces

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Agile work products (2)

• Graphical models with textual descriptions
• Activity diagrams
• Sequence diagrams
• Use case diagrams
• …
• Glossary of business terms
• Non-functional requirements

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Granularity of requirements

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Today’s Lecture – How is RE done in agile processes?

• Agile motivation and mindset
• Fundamentals of agile RE
• Agile RE work products
• Agile RE techniques

​

Text questions to (562) 684-8307

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Agile requirements elicitation

• Intensive communication between all stakeholders
• Mostly informal, direct (does not scale well)
• Quick feedback through prototypes and product increments

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Agile requirements documentation

• Avoid documentation overkill and achieve a minimum set of useful documentation
• Documentation done for:
• Legal purposes
• Preservation purposes
• Communication purposes
• Thinking purposes

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Agile requirements validation

• Validation primarily done through early and frequent feedback on product increments
• If the increment does not meet the requirements of stakeholders, the missing requirements are put into the product backlog and evaluated/prioritized with all other backlog items

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Agile requirements management

• Backlogs:
• Designed to keep only the latest and best version of all requirements yet to be implemented
• Their items are typically deleted or archived as soon as they are implemented
• Backlog requirements management activities:
• Prioritization
• Estimation

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Summary – How is RE done in agile processes?

• Agile processes welcome changes in requirements, believe in face-to-face conversation, and consider documentation as just a means to and end
• Agile RE processes are continuous and iterative, and focus on value, simplicity, and frequent feedback
• Agile work products include the backlog, vision, context model, graphical models, glossary, and NF requirements

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