January 2009

Monthly Archive

Agile 2009 – Wear Your Badge Proud!

Posted by on 28 Jan 2009 | Tagged as: Uncategorized

Show off your attendance at Agile 2009 with the badges below. Place these badges on your blog, web site, emails, and newsletters to get the word out about Agile 2009. The link to the official Agile 2009 web site is http://agile2009.agilealliance.org/.

Register for Agile 2009

I am speaking at Agile 2009

We sponsor Agile 2009

What is Architecture?

Posted by on 19 Jan 2009 | Tagged as: Agile, Architecture, General, IASA, Leadership, Product Owner, Scrum, Software Architecture, TDD, XP

Talk about a loaded term. Even the term itself, “architecture”, when used in the Agile community can start a heated discussion. When I was coordinator of the International Association of Software Architects Puget Sound chapter, the discussions about “what is architecture” caused passionate debate. I am sure this entry will get some interesting comments, as well.

I don’t believe that this entry will solve the question but I hope to at least give some focus for teams who are dealing with the structural integrity of their applications. First off, a definition of “architecture”:

architecture: noun – “the art or practice of designing and constructing…” or “the complex or carefully designed structure of something” or “the conceptual structure and logical organization of a computer or computer-based system”

Each of these definitions interests me but to put them to practice is quite difficult. They are left to interpretation about what is design, construction, structure, conceptual, and logical. Earlier interpretations of this term interpreted these to mean the high-level structure, architectural style, and finally the stuff that is too expensive to get wrong.

It seems to me that my interpretation is a bit different. Working with tools, practices, and processes over the past 15 years has guided me to a different conclusion. I believe that architecture is how it is SAID:

Structure – how the pieces (components) create a solution (application)
Alignment – the degree to which the application or enterprise structures align to current business objectives and strategy
Integrity – the components that provide stability to the structure (application or enterprise) (ie. automated tests and builds, service-level agreements, network infrastructure, etc…)
Design – a way to conceptually communicate the planned or implemented structure of a component, application, or enterprise (ie. system of names, XP practice of Metaphor, information radiators, etc…)

Using these as the basic building blocks for teams to focus their efforts can be helpful.

The structure is the reality of the solution’s construction. If the structure is too brittle or complex to support future needs then the structure is not sound. If you have been in the software development industry for even short period of time you have probably seen applications that are too brittle or complex.

If the application or enterprise structures are not aligned with current business needs then the value of those structures have deteriorated. We sometimes keep a specific architecture and force-fit new business needs into it because it once was the right architecture to have or we paid a bunch of money for it. Continual restructuring of our architecture to meet today’s business needs is important.

Providing supports to our structure allows for it withstand changes in the environment such as new business needs and updates in technology. Automated tests and builds help us keep the structural integrity of our applications intact while these changes are introduced into our applications and enterprise.

Communicating the conceptual structure of a component, application, or enterprise is important because it is common for new people to work on them and for those structures to interact with other components and applications. Getting someone up to speed on a component or application involves verbal, tactile, written, and visual examples. Much of what is needed can be kept in or close to the codebase along with conversations with existing developers. It is important to understand how components and applications are currently structure conceptually so we can discuss their interactions with other components and applications. For instance, should we connect via library, SOAP, RPC, or REST?

When I think of application architecture I want to focus on just a few principles:

  • Application architecture is about changeability, not longevity
  • Application architecture decisions should be made closest to where they are implemented as possible
  • Application architecture design is not only about our ability to design a solution but also knowing what components, applications, and solutions already exist
  • The value for change in a component’s, application’s, or enterprise’s architecture is directly proportional to the cost of not addressing

If the structure is not able to change as the needs of our business change then the solution will become a liability. If someone other than those who are constructing components and applications are deciding on architecture decisions then there will be important information lost in translation between the two. If we keep using the same design hammer (ie. always using 3-tier or IoC for everything) then we are not allowing the strongest solutions to emerge. The value of architecture can usually be described by the cost incurred if it is not taken care of.

Well, let the onslaught of comments commence. I have put out my ideas on architecture. There are many more out there to discuss and I am sure I will hear some of them. I will finish this entry with a quote from Martin Fowler’s “Who Needs an Architect?” article:

“I define architecture as a word we use when we want to talk about design but want to puff it up to make it sound important.”

See You at SD West 2009

Posted by on 15 Jan 2009 | Tagged as: Acceptance Testing, Agile, Architecture, General, Leadership, Open Source, Product Owner, Scrum, Software Architecture, TDD, Travel, User Stories, XP

I’d like to invite you to join me at …

SD West 2009 Conference & Expo
March 9–13
Santa Clara Convention Center, Santa Clara, CA

I’m pleased to announce that I’ll be teaching the following session at SD West 2009:

“Managing Software Debt: Continuing to Deliver High Value as Systems Age” on Friday, March 13th from 3:30-5:00pm

SD West is where the software development community gathers to learn about the latest business-critical technologies, network with peers, connect with innovative vendors and get inspiration from industry visionaries. The comprehensive conference program covers today’s most important topics including cloud computing, concurrent programming, dynamic languages, agile processes, security, testing and much more.

Super early bird conference discounts of up to $400 expire Friday, January 16.  As a speaker, I can also offer you an additional $100 off the VIP Pass. Simply register at http://www.SDExpo.com with the code 9ESPK to get your discount.

Check out all the excellent educational opportunities SD West 2009 has to offer at http://www.SDExpo.com.

I look forward to seeing you in Santa Clara!

OK, I Created a Wordle, Too

Posted by on 05 Jan 2009 | Tagged as: General

Here is the wordle for this blog site:

Wordle: Chris Sterling's Blog Wordle

User Stories Gone Wild!

Posted by on 03 Jan 2009 | Tagged as: Acceptance Testing, Agile, Architecture, General, Leadership, Product Owner, Scrum, Software Architecture, User Stories, XP

The thought of less documentation is appealing to many in the software industry. Reducing the specificity of our requirements can have tremendous value but some go too far. One of the big myths about Agile software development is that Agile means no more documentation. This was not the purpose of the Agile Manifesto value “Working software over comprehensive documentation”. The ideas was that only the documentation that supports the creation of working software should be created. There are many reasons for software to have documentation:

  • Maintainability
  • User manuals
  • Training
  • Communication
  • etc…

Since the idea of Agile software development is not to remove all documentation from software delivery then what is the right amount of documentation? Of course, the answer is it depends but we won’t leave it at that. This article will focus on one area of documentation and that is specifying what users want.

User stories were popularized by Mike Cohn with his book “User Stories Applied”. Many people do not read and take in all of what is provided in Mike’s book before using user stories to capture user desired functionality. Instead they may be introduced to it on the Internet, through a seminar, or in training. The appeal of user stories is they are short statements that are easy to write and fit on 1 index card. The problem, as Ron Jeffries explains it in his article “Card, Conversation, Confirmation”, is the statement written on an index card is not enough information for the development to implement without providing some clarity through conversation with someone who represents the user’s desires. So the first way that user stories “GO WILD!” is:

Stakeholders expecting that a statement written on an index card is enough for the team to implement what they desired in the software

And this can be more generalized as:

User stories inappropriately used and becoming just bad specifications

Development must have conversations with people knowledgable about the user story domain to clarify the desired functionality. And as Ron rightly describes, conversations may be supplemented with documentation when needed. This could be in the form of an user interface design, usability study, business rules, acceptance tests, and any other format necessary for the development team to implement the user story satisfactorily. During the conversation new understanding and clarity of the user story specifics will be drawn out. The next way user stories “GO WILD!” is:

Acceptance criteria (or “Confirmation” as Ron puts it) for the user story is not captured and many times forgotten during implementation

It is important that the development team and domain experts write down important nuggets of knowledge about the desired functionality. This could be as simple as writing it down as bullet points on the back of the index card or creating skeletons of acceptance test cases.

Sometimes teams come across user stories that seem either too ambiguous or potentially mammoth in size. There are some great indicators in the user story text that I have found over the years while working with them over the years. Here are a few ways that user stories “GO WILD!” along with ways to deal with them when they do:

Using conjunctions within the user story statement

Whenever I see an “and” or “or” or “if” or “until” or… well you get the picture… this is an indicator to me that more than one piece of functionality is being described. This is an opportunity to split the user story into multiple user stories usually right where the conjunction was put in.

Describing too much about “how” to implement the user story

It has been common in my experience to see business analysts or technical writers creating user stories to support a Scrum Product Owner or stakeholder group in defining their desired features. You might see phrases such as “when they click on … button”, “drop down”, and “using Excel” which are specific about the “how”. In the past, these people were asked to describe the functionality so it was clear for programmers to code and testers to verify. Now we are asking them to write user stories that describe “what” the user wants and not “how” to implement it. This is a problem since they have used the “how” to make clear requirements for the development team to implement. Agile teams are expected to take more responsibility in defining “how” the software is implemented. This includes providing their input on specifying and designing the software. Many times I have seen specification of features get simplified or enhanced through the conversation between development team and domain experts. We want this to occur more often since these interactions will increase software features delivered and improve the product for its users.

Can’t describe the value provided to the user for the desired functionality

There has been more than one time that I have asked “why are we implementing this user story” and was not provided a satisfactory answer. I may have gotten an answer like “because it is defined in the requirements document”, “because it was prioritized high”, or “because the CEO wanted it”. All of these may be good enough reasons to implement the functionality but it is less likely that the development or domain experts will implement it masterfully given the lack of understand around what the user wants to do with this functionality. Understanding how a user story fits into the bigger picture is important since it will enhance the conceptual integrity of the software overall. When software is implemented by generating many disconnected components and integrating them together into a cohesive package the software tends to become inconsistent in its usage with lots of hidden but potentially useful functionality. Ask yourself when writing a user story why would the user want this functionality. You can use the user story template:

As a [user role] I want to [do something] so that [I gain some benefit or value]

By address the “so that” clause you will provide more understanding of how the functionality fits into the larger picture. Or you may find out that it is not useful at all. In that case, you can throw it away and work on something of more value to your users.

Writing technical user stories in which the value is not understood by the Product Owner or stakeholders

Technical user stories tend to get deprioritized since they are not easily assessed for value by most non-technical people. I have found that it is essential to describe why we have new technical needs or what the cost of not addressing a system’s quality attribute such as scalability could be. I have written an earlier post on this regarding a term coined by Mike Cohn called “abuse stories”. The idea is to capture the cost of not addressing an architectural or infrastructure need by describing it from an abuser of the software’s point of view. Writing technical needs in a user story format is not necessary but may be helpful while building trust between the development team and stakeholders. Sometimes project stakeholders believe that time and money is getting wasted on technical perfection. By writing the abuse story a development team can show that these technical needs are not just wasted efforts but provide value to the software. It is hoped that over time a team can just let their Product Owner or stakeholder group that there is a technical need that must be prioritized before particular functionality should be implemented and that will be enough.

Now that you know some ways that your user stories can “GO WILD!” it is time to tame those user stories so that your software can be the best it can be. Happy story writing! And, oh yeah, happy new year 2009!