Towards a Catalog of Scrum Patterns

Posted on December 6, 2012 by charlesbradley

I’ve been thinking a lot lately about Scrum patterns.  To that end, I’ve drafted a conceptual model, which is depicted in the below image.  (You may want to click the image twice to see a bigger view of it)

ScrumPatternsOverviewOnePage

“Sprint Progress Monitor” is my term for what used to be called the “Sprint Burndown.”  In the 2011 Scrum Guide, Sprint Burndowns were no longer required but some way of monitoring sprint progress, via summing the remaining work, was still required.  In the Scrum Guide, it is made clear that these practices can be implemented using several techniques, and “techniques may vary” from team to team.  So, this is what inspired me to use the term “Scrum Technique Pattern.”  A Scrum Technique Pattern(STP for short) implements the intentional gaps left by the Scrum Guide.  Teams can inspect and adapt their technique patterns, while still fulfilling the Scrum framework.  Said another way, there are intentional “variation points” in Scrum, and the STP’s are different ways of implementing those variation points.

“Optional Scrum Patterns” are patterns that can be used in conjunction with Scrum, but are not specific implementations of Scrum techniques as specified or required in the Scrum Guide.  These can be just about anything, but they must follow and/or support Scrum principles in order to be considered as an Optional Scrum Pattern.

I also see the need for the ability to create a “mashup” of different Scrum patterns to create a set of practices and techniques for a particular team or context.  For instance, we might start out with a Scrum Starter Kit that includes things like:

  • Holding a Release Planning meeting every 2-3 months (OSP)
  • 2 Week Sprints (STP)
  • Using Story Points to estimate Product Backlog Items(STP)
  • Using Ideal Hours to estimate Sprint Backlog plan items(STP)
  • Doing a typical burndown chart to sum the remaining work for the sprint(STP)
  • Representing Undone Work(OSP)
  • Doing the typical “round robin” style of the Daily Scrum(STP)
  • Doing a fairly typical “Plus-Delta” retrospective analysis(STP)

Any of the above patterns could be interchanged with other patterns, and the Scrum implementation would still conform to doing correct Scrum.  Presumably the change to different patterns would be an attempt to improve a team’s ability to delight their customers and users.

Who writes these patterns?  Where do they come from?

In a word, anywhere.  I’ve seen dozens of them on the internet and in books.  I’ve documented a few original ones myself(though many of mine are adapted from others, and I would make every reasonable attempt to give credit where credit is due).  I would not be attempting to create all of these patterns, but to assemble them and label them so Scrum practitioners can easily understand which of them are optional, and which are fulfilling required practices of Scrum.  Of course, it will also become helpful to understand where these patterns fit into the grand scheme of Scrum, and I have some ideas along those lines, too.

I will keep iterating on this concept, and I hope to get back to you with more on this topic in the future.

Filed under: Agile, Organizational Change, Release Planning, Scrum, Scrum Adoption, Scrum Strategies, ScrumMaster Tips, Story Points, The Daily Scrum, The Retrospective, The Sprint Review, User Stories | 6 Comments »

Agile2012 Q&A – Ron Jeffries and Chet Hendrickson on Simplicity

Posted on August 24, 2012 by charlesbradley

I had the good fortune of being in a Q&A Session at Agile2012 with Ron Jeffries and Chet Hendrickson, early pioneers of Extreme Programming(XP), and both now Certified Scrum Trainers. Ron and Chet were sitting on the “expert couch” taking questions from the audience. I decided to break the ice by going on stage (questioners had to sit in the “therapy” chair next to the couch, and were time-boxed to 10 minutes) and asking them the first question of the Q&A session.

Keep in mind that this is just my recollection of the event. I’ll encourage anyone present to correct or add to what was said from their recollection. I lobbed them a softball of sorts. It wasn’t a hard question, but I wanted to hear their answer as Agile Manifesto authors. A friend in the biz had recently asked this question of me:

How do you interpret this Agile Manifesto principle?

  • “Simplicity–the art of maximizing the amount of work not done–is essential.”

I asked Ron and Chet to give some background on what that principle was meant to convey. Ron spoke from a programming perspective mostly. He said that simplicity refers to Kent Beck’s 4 rules of simple design. Kent’s definition stresses:

“…In priority order, the code must:

  1. Run all the tests
  2. Contain no duplicate code
  3. Express all the ideas the author wants to express
  4. Minimize classes and methods…”

The above is copied from Ron’s article on Emergent Design. Ron added that simpler is often simpler than you think, and simpler is often smaller than you think. He mentioned the phrase “the simplest thing that could possibly work” as a reminder to keep design and code simple.

Chet then chimed in on the topic of slicing stories smaller. By slicing them smaller, we can de-prioritize smaller stories in a more surgical way, thus avoiding work that is not needed right now, and may be never needed. There are also other huge benefits to smaller stories in that they are easily digestible, and thus less work to understand and implement. Chet stressed that smaller is probably smaller than you think. I then chimed in and mentioned a concept I had read in one of the XP books. If all of the details of your user story won’t fit on a card, then you should use a *smaller* card so that your stories are sized smaller because you’re clearly making stories too large and probably need practice at making them smaller. Chet finished by mentioning that, while simple is simpler and smaller than you think, you should be constantly inspecting and adapting your “simplicity” optimum.

Filed under: Agile, Extreme Programming, Organizational Change, User Stories | Tagged: | 2 Comments »

Handling Non Functional Requirements in User Stories and Scrum

Posted on June 28, 2012 by charlesbradley

Handling non-functional requirements in User Stories can at first seem difficult, but as it turns out, there’s a pretty easy way to handle them.

For performance requirements and many other non functional requirements(NFR’s), one can use constraints and stories. What I usually coach is to create a story to document the NFR and define story tests for it. Then, I suggest adding the story tests as a “constraint.” A constraint is something that all implemented stories(features and functionality) must comply with. If you’re using Scrum, then you’ll want to add something like this to your Definition of Done(DoD): “All stories must comply with all of the story constraints.”

Example

Step 1: Identify and quantify the constraint and put it in terms that your users and business stakeholders will understand.

Story Title: System response time

  • Story Test #1: Test that the system responds to all non search requests within 1 second of receiving the request
  • Story Test #2: Test that the system responds to all search requests within 10 seconds of receiving the request

Some things to keep in mind:

  • If you cannot quantify the story in concrete terms, this should be a bad smell that usually indicates a requirement that is too vague to be implemented. Vague NRF’s have the same problems that vague functional requirements do: It is hard to answer the question “How will I know when this story is correctly done?”
  • Be sure not to specify a technical solution or implementation in the story, because stories are about “The What”(“What the user wants”) and they are not about “The How” (“How this is implemented”).
  • Plan, estimate, split(if necessary), and implement this story like all other user stories, as part of the Product Backlog(Scrum).

Once this story is complete, the entire system will be in compliance with this particular constraint.

If your constraint is not system-wide or far reaching:

  • Just add it as a story test for that story. But again, specify the requirement, not the implementation, in terms the business stakeholders will understand.

The decision to create a constraint or not will rest on whether the constraint should be taken into account in at least several future stories(or system wide). If it will apply to several future stories, then create a constraint. If it won’t apply to several future stories, then just add the NFR as a story test to the stories that it applies to, or create a separate story to comply with the NFR in the small part of the system that requires it.

Step 2: Add the Story Tests to your list of constraints (and to your Definition of Done if you’re doing Scrum)

Publish your list of constraints(and/or DoD) somewhere that is highly visible. Even if you keep your constraints electronically, print them out in large print and post them somewhere on your Scrum board or in your team area.

Constraints
  • Test that the system responds to all non search requests within 1 second of receiving the request.
  • Test that the system responds to all search requests within 10 seconds of receiving the request.
  • Test that the system logs a user out after 10 seconds of inactivity and redirects their browser to the home page.
  • Test that any update to a person’s payment information(anywhere in the system) is logged to the payment_preferences log, along with the following information:
    • IP Address of logged in person
    • Old preference value, new preference value
    • Date/time of change
  • Test that any time a person’s credit card number is shown in the application, that only the last 4 digits display.

A note about Story size estimating:
Once a new constraint is added to the system, any stories in the product backlog that will have to comply with this constraint may need re-sizing if there is material time required to comply with the constraint. Said another way, all estimates for future stories will need to take into account the fact that the constraint must be complied with in order to call the story “done.”

If you’re doing Scrum, then add the constraints to your Definition of Done.

Definition of Done
  • All stories must comply with all of the story constraints<link to constraints page on wiki>.
  • All code must be peer reviewed within 4 hours of checkin.
  • If a change is made to the web services interface, the change must be documented on the official web services api wiki page<link to api on wiki>.
  • All code must have automated testing that is consistent with the “Automated Testing Guidelines”<link to guidelines on wiki>
  • Any change in of functionality that is visible in the GUI must be at least tested manually(automated tests also acceptable) against the integration environment before making the functionality available for a QA review.

Another note about Story size estimating:
Like I said above for the constraints, the Definition of Done should always be taken into account when sizing user stories. It might help to bring a copy of your DoD to your grooming and planning meetings to remind developers what all is included in their estimates.

Related Articles

Filed under: Product Backlog, Product Owner Tips, Scrum, User Stories | Leave a comment »

A Visual Diagram of the User Story Life Cycle

Posted on June 26, 2012 by charlesbradley

This blog post is now deprecated.  Please see the new updated blog post:

https://scrumcrazy.wordpress.com/2013/06/13/new-and-improved-user-story-lifeycle-diagram-free-creative-commons-pdf-download/

 

Filed under: Product Backlog, Product Backlog Grooming, Product Owner Tips, Release Planning, Scrum, ScrumMaster Tips, User Stories | 2 Comments »

My Preferred Agile, Scrum, and XP Resources

Posted on June 4, 2012 by charlesbradley

If you’re printing this post, it can be found online at: http://www.scrumcrazy.com/My+Preferred+Agile%2C+Scrum%2C+and+XP+Resources

A friend recently asked me this question:

What would you recommend in terms of the best book(s) to learn about Agile (Scrum) with XP practices? That is, if you had a team of developers who were newbies to Agile, Scrum, and XP, what books/articles would you give them to bring them up to speed on what they should be doing and how they should be doing it?

This question from my friend is a very tricky one, in that it is very broad and generic, and my friend gave me no extra team or organizational context to go on, so about all I can do is give a generic answer, and that is what I’ve done below. If you’re looking to combine Scrum with XP practices, be sure and see Kniberg’s book under “Scrum” below.

Don’t have time to read all of these? Well then, read the first couple from each category, and then continue working your way down each list.

My Preferred Resources

All are in order of my personal preference in each category.

Scrum

  1. The Scrum Guide (Must read for all)
  2. Deemer, et al. “The Scrum Primer”
  3. Cohn’s _Agile Estimating and Planning_ (Must read for Scrum Masters)
  4. Pichler’s _Agile Product Management…_ (Must read for Product Owners)
  5. Cohn’s _Succeeding With Agile…_ (Must read for Scrum Masters once they have a few Sprints under their belts)
  6. Kniberg’s _Scrum and XP From the Trenches_ (Note that there is a free PDF download of this book if you register with InfoQ – something I recommend anyway)
  7. Derby/Larsen’s _Agile Retrospectives_

XP (Extreme Programming)

  1. Jeffries’ “What is Extreme Programming?”
  2. Jeffries’ _Extreme Programming Installed_
  3. Koskela’s _Test Driven…_
  4. Martin’s _Clean Code_
  5. Feathers’ _Working Effectively With Legacy Code_
  6. “The Rules of Extreme Programming”
  7. Wiki entry on XP Practices

Agile/XP Testing

  1. Summary of Lisa Crispin’s Presentation to Agile Denver on Test Automation
  2. Cripin’s “Using the Agile Testing Quadrants”
  3. Crispin/Gregory’s _Agile Testing_
  4. Crispin/House’s _Testing Extreme Programming_
  5. Cohn’s “The Forgotten Layer of the Test Automation Pyramid”
  6. Osherove’s _The Art of Unit Testing_

User Stories (which originated in XP)

  1. My “User Story Basics” article and all of the links at the bottom of that article
  2. Cohn’s _User Stories Applied_
  3. Cohn’s _Agile Estimating and Planning…_ (Chapter 12: Splitting User Stories)
  4. Lawrence’s “Patterns for Splitting User Stories”

Special Agile Topics (if applicable)

  1. Deemer’s “The Distributed Scrum Primer” (If some of all your team is remotely distributed)
  2. My article entitled “The Role of Managers In Scrum” and all of the links at the bottom of that article
  3. Larman/Vodde’s _Scaling Lean Agile…_ (If your Agile transformation involves a very large organization)

Filed under: Organizational Change, Product Backlog, Product Backlog Grooming, Product Owner Tips, Release Planning, Scrum, Scrum Adoption, Scrum Strategies, ScrumMaster Tips, Sprint Backlog, Sprint Planning, Story Points, The Daily Scrum, The Retrospective, The Scrum Artifacts, The Sprint Review, The Sprint Time-boxes, User Stories | 8 Comments »

User Story Basics – What is a User Story?

Posted on May 3, 2012 by charlesbradley

What is a User Story? I’m glad you asked!

First of all, it’s important to say that User Stories are not a part of Scrum as defined in the required practices in the Scrum Guide. User Stories are but one way to represent Product Backlog Items in Scrum, and while it is the most popular method used, it is not the only method. Still, though, I would like to remind you that the User Stories practice is totally independent of Scrum, and thus it is not defined by Scrum. As such, everything else in this post is about the User Story practice and not Scrum itself.

Beware the common misconception!

There is a common misconception in the industry that a User Story is a sentence like:

  • As a <user> I want <some functionality> so that <some benefit is realized>.

THIS IS NOT A USER STORY!!! This is the biggest User Story trap in existence! See Trap#1 and #8 of my article on User Story Traps.

What is a User Story?

<Definition>
A user story describes functionality of a system that will be valuable to a Non Development Team(NDT) stakeholder of a system or software. User stories are composed of three aspects:

  • a written description or short title of the story used as a token for planning and as a reminder to have conversations
  • conversations about the story that serve to flesh out the details of the story
  • acceptance tests that convey and document details and that can be used to determine when a story is complete

</Definition>

What do they mean by Acceptance Tests?

Typically, in the context of a User Story definition, we mean tests that are represented by conversations, textual descriptions, tables, diagrams, automated tests, and so forth. When these Acceptance Tests are applied to the completed, implemented User Story, all of the tests should pass, and will thus prove that the story has been implemented correctly. If some functionality was not covered in a User Story acceptance test, then it wasn’t a requirement for that particular User Story.

Technically, in the context of a User Story definition, an acceptance test need not be automated or implemented. At the minimum, it should be described conceptually. The test should then be executed in order to prove the story and get acceptance, whether that be a manual or automated process. If your conceptual acceptance tests are described by one or more automated tests, then that is generally a much better practice, but not absolutely required.

Acceptance Tests should be automatable about 90+% of the time, though again, it is not required that they be automated. Having said all of that, when teams strive for development speed and quality, very few get far along that road without automating a large portion of their acceptance tests.

Acceptance Tests, in the context of User Stories, are also sometimes called Story Tests, Acceptance Criteria, Conditions of Satisfaction, and Test Confirmations.

Ron Jeffries, one of the co-inventors of User Stories and Extreme Programming (where the User Story practice comes from), has a good article that also describes User Stories in a basic way.

When do these Conversations and Acceptance Tests get created?

Typically, this happens in weekly Product Backlog grooming(also known as a Story Writing Workshop, Story Grooming, etc) sessions, but can also happen informally. The most effective backlog grooming includes some stakeholder/user representatives, the entire development team, and a Product Owner (Scrum) or Customer(XP). These sessions happen weekly and usually last 1-2 hours each. The goal of the sessions is to get stories that are “ready”, meaning the team has a shared understanding of the Acceptance Tests, and has the vast majority of the information they need to implement(code) the feature. See What does Product Backlog Grooming Look Like? for more on that topic. Keep in mind that sometimes a single User Story will be discussed in 2-3 grooming sessions before it is “ready”, especially if there are open questions or complex logic involved.

Frequently Asked Questions

Should I use a User Story to represent bugs/defects in a system?
The short answer is “it depends.” If it is a legacy or deferred bug, then yes, and it should end up on the Product Backlog(story points assigned). If it is a bug that was introduced since Scrum/Agile was put in place, then no, and it should end up on the Sprint Backlog(no story points assigned). See One way to handle Bugs and Production Support in Scrum for the longer answer.

Where do I get more info?

Filed under: Product Backlog, Product Backlog Grooming, Product Owner Tips, ScrumMaster Tips, Story Points, User Stories | 9 Comments »

Handling Scope Changes Mid-Sprint in Scrum

Posted on April 26, 2012 by charlesbradley

The first thing about handling scope changes mid-Sprint is to recognize what type of scope change it is.

Bug or Production Support request?

If it’s a bug, or a production support research request, then my preferred method is to use One way to handle Bugs and Production Support in Scrum . As it says in that article, I hope you don’t need that chart. If you’re one of those teams where such bugs and production support requests are very rare (say, on average, once or less every 2-3 months), I’d say just do it and you can choose whether to make it a Product Backlog Item or put it on the Sprint Backlog. You’ll probably lean towards PBI if it’s a big thing, or put it on the Sprint Backlog if it’s a small thing.

Scope Change to PBI in Progress

If it’s a scope change to a Product Backlog Item in progress, my hope is that this means a new or changed acceptance/story test of some sort. If you’re not practicing Acceptance Test Driven Design, you should be! For you non ATDD types, the old school terminology for this is a “requirement change.” I’ve been around the block a few times coaching Scrum Teams on this scenario. My best advice is this:

  • If the change in scope is likely to increase the originally estimated size for the story by more than about 10%, then the change should be a new Product Backlog Item by itself. You may need the whole team to re-estimate the newly changed story.
  • If it is less than about 10%, then just change your acceptance tests, do it alongside the current PBI, and move on with life.

Swapping in the new PBI

If the scope change does result in a new PBI, then in rare cases where it is strongly warranted, a Scrum Team should be flexible enough to swap that PBI in and do it in the current Sprint. However, this usually means some other PBI will have to be swapped out of the Sprint as well. If these kinds of “swaps” begin happening regularly, then your team needs to do a root cause analysis on the swaps in the Retrospective.

  • In this scenario, don’t forget that the new, urgent PBI needs to be groomed, sized, and tasked out on the Sprint Backlog. Get all of your team together and you can usually do this in a matter of minutes.

Filed under: Product Backlog, Scrum, Scrum Strategies, ScrumMaster Tips, Sprint Backlog, User Stories | Leave a comment »

Story Testing Patterns – My Recent Presentation at Mile High Agile

Posted on April 20, 2012 by charlesbradley

You can now find my recent presentation(along with all the handouts, etc), “Story Testing Patterns” on my website here:

http://www.scrumcrazy.com/Presentation+-+Story+Testing+Patterns

Feel free to add any comments here on my blog.

.

Filed under: Product Backlog, Product Backlog Grooming, Product Owner Tips, User Stories | Leave a comment »

One Way to Handle Bugs and Production Support in Scrum

Posted on April 18, 2012 by charlesbradley

This article has been updated and republished here.

Filed under: Bad Smells, Organizational Change, Product Backlog, Scrum, ScrumMaster Tips, Sprint Backlog, Sprint Planning, The Daily Scrum, The Retrospective, User Stories | Leave a comment »

A User Story Checklist

Posted on April 16, 2012 by charlesbradley

Sometimes it’s difficult to determine if something is a User Story or not.  Not everything a software team does is a User Story.

In my other article, User Story Basics , I talk about the definition of a User Story.  I will use that definition to make a checklist of characteristics a User Story must have.

  1. Does the story describe new or changed functionality in the system under development?
  2. Is the functionality primarily of value to a stakeholder playing a role other than the role of “developer on the development team for the system under development”?  Said another way, is the functionality primarily of value to a Non Development Team stakeholder?
  3. Is there a fairly unique written description of the story?  (This can be just a couple of words, like a title)
  4. Have conversations about the story, that clarify story details, taken place?
  5. Does the story have acceptance tests that convey and confirm when the functionality of the story is complete, correct, and present in the system under development?

If you cannot answer “Definitely, yes!” to all of the above 5 questions, then it is almost always… NOT a User Story.

With respect to Question #2, I tend to define ¨developer” fairly broadly, like Scrum does.  From the Scrum Guide: “[Development] Team members often have specialized skills, such as programming, quality control, business analysis, architecture, user interface design, or data base design…”.  On some development teams, people who play a role of developer also play a role of “product support member” for the system under development.  In this way, sometimes User Stories describe functionality that is important to someone doing production support.  Other than this one exception, though, functionality and features that are primarily of importance to developers are almost always not considered User Stories.  On the other hand, there is nothing wrong with a developer suggesting some functionality to a NDT Stakeholder, and/or convincing a NDT Stakeholder that some functionality will be primarily of value to that stakeholder.  If that stakeholder agrees, then you can re-classify that functionality as a User Story… so long as you can say “Yes” to all of the other questions above.

A question that often comes up is, “Should Fixing a bug be represented as a User Story?”  The answer is, it depends.  The only question we might have trouble answering “Yes” to is #2.  The first thing you should ask is this: What (already delivered) User Story Acceptance Test(or tests) fails due to this bug?  If you can’t point to one specific acceptance test, then it’s probably a missed acceptance test(meaning one was overlooked when the story was originally implemented) or a legacy bug(a bug introduced before you adopted User Stories), in which case, the bug should almost always be represented as a new User Story.

Filed under: Bad Smells, Product Owner Tips, Scrum, ScrumMaster Tips, User Stories | Leave a comment »

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