Charlie Alfred’s Weblog

October 18, 2009

Putting the Proposition back into Value Propositions

Filed under: Uncategorized — charliealfred @ 8:25 pm

Value Propositions are as to marketers, as Gannt charts are to project managers or debuggers are to software developers.

But value propositions can and should be more than marketing hocus pocus.  What value propositions promise, imply, conditionally promise, or avoid mentioning at all are a reflection of what is important to the business.  This conviction works its way into philosophies of product design and priorities for organizing and staffinf up service operations.

This article ( will explore the nuances of value propositions, with some modern day examples to illustrate the points.


September 6, 2009

SCRUM and Architecture – Do they mix?

Filed under: Uncategorized — charliealfred @ 9:08 pm

SCRUM is a popular agile development methodology that was first popularized in the early 1990’s by Ken Schwaber and others.  It features short (2-3 week) development sprints, development team accountability, and separation of the chickens (management stakeholders) from the pigs (developers).

Software architecture is a high-level approach to the conception of a system.  It was initialy popularized in the mid 1980’s by the writings of David Garlan and Mary Shaw.  The Software Engineering Institute (SEI), affiliated with  Carnegie Mellon University has been a major force in spreading the software architecture mantra.  Today, virtually every software development group of 12 people or larger has a software architect on staff.

However, during the past 20 years, SCRUM and Software Architecture have lived a somewhat tenuous existence.  Like other agile methods (such as XP), SCRUM is not a believer in big design efforts up front.  Planning mainly consists of choosing a team, and capturing and prioritizing a number of user stories.  From that point, the development team and product manager select the set of stories to work on during each sprint, and the developers figure out how to design the solution.

The SCRUM methodology is intended to have fast reaction times to changes in  requirements or priorities.  During a sprint, no course changes are permitted, but between sprints, anything goes.  If the changes are significant, the development team relies on refactoring existing software and leveraging automated unit tests to ensure no regressions.

This article (located at explores the relationship between SCRUM  and Software Architecture, primarily from the perspective of a recent project that tried to blend both.

March 29, 2009

Architecture Core Concepts

Filed under: Uncategorized — charliealfred @ 8:11 am

Around two years ago, I started writing a blog on value modeling and architecture.  The results of this effort are posted in the pages of this blog.  I will be taking a hiatus (hopefully brief) from my writing – predominately due to time constraints.  So, I thought it would be useful to wrap up with a summary page, one that attempts to capture the concepts that I think are essential to all software architects (and quite possibly other types of architects, too).   In the following page, I identify 8 core concepts and describe each with a short paragraph.  Following the paragraph, I include 2 or 3 links to other articles in this blog that expand on that concept, for anyone looking for more information.

12:26 PM 3/29/09: Added a new diagram and paragraph to the summary

March 21, 2009

More Conceptual Distance

Filed under: Uncategorized — charliealfred @ 1:08 pm

Most of us have watched our retirement portfolios and children’s college funds shrink by 50% during the past six months.  As painful as this is, there are lessons to be taken away.  No, I’m not referring to the people who want to lynch those who received million dollar bonuses from AIG.  And I’m not even referring to the people who now want to regulate anything that moves.

No, I’m talking to the people who want to understand some of the fundamental causes, and think about how little understanding of the risks caused by the real underlying factors actually made it through the “split pea soup” we happily call communication in our day and age.  How will the world function when information that must be conveyed won’t fit in a cell phone text message?”  Do we coast merrily along hoping that our surface-level assumptions hold water?  Or do we cross our fingers and hope that the other guy has the answers (then point an appropriate finger when things go wrong)?

I don’t profess to know the answer here.  Too much depends on the fickleness of human behavior.  But I think that the excellent March 2008 article in Wired, written by Felix Salmon, is a great place to start, and I hope that the article that appears in helps to frame it properly.

February 21, 2009

Pattern Languages

Filed under: architecture,pattern language,patterns — charliealfred @ 2:05 pm

It has been 32 years since Christopher Alexander wrote A Timeless Way of Building, and 15 since the Gang of Four wrote Design Patterns.  Today, virtually everybody working in software development can tell you what a Singleton or a Factory is.  And that is a very good thing.  But, is it enough?


Christopher Alexander talks about the preeminence of a pattern language — a system of interrelated patterns that combine and synergize to resolve all of the forces in the larger context.  No matter how large your catalog of design pattern is, you don’t have a pattern language until you knit them into a system.  Sure sounds like architecture to me!


The following essay (  explores Design Patterns, A Timeless Way of Building, and several related topics to try to understand how, as an industry, we can start putting the language back into pattern languages.  And along the way, we identify a North Star, for those who believe that pattern languages are an important step in the maturation of software development.

January 18, 2009

Seven Deadly Sins

Filed under: Uncategorized — charliealfred @ 4:13 pm

Most of us are familiar with Dante’s “Seven Deadly Sins” – lust, gluttony, sloth, greed, envy, pride, and wrath.  And many of us remember the vivid depiction of these sins in the movie Seven.

Imagine if Dante were alive today.  What might he have to say about the state of software product development?  Few would doubt that this activity has its own special collection of aberrant and deviant behaviors.  Perhaps the sins of software product development aren’t as intentional as the original set, but they sure can impete and frustrate the best efforts of those of us who work in this space.

So, the article is devoted to exploring the Seven Deadly Sins of Product Development.  It was fun to write.  I hope it is enjoyable and informational to read.

December 21, 2008

My two-cents about architecture style

Filed under: Uncategorized — charliealfred @ 6:16 pm

Recently, the topic of architecture style has gotten more discussion.  A colleague, Ruth Malan, noted that the Microsoft Application Architecture guide has devoted a chapter to the topic.  Ruth contrasted their definition with the one she published in her blog in July 2008.  In addition, architecture giants, such as David Garlan, Mary Shaw, and Roy Fielding have each weighed in with their own definitions.

So why does this matter?  Why should a practicing architect care who specifies which definitions and whether or not they are consistent.  Does anybody’s work day really depend on a definition?

Personally, I think it can.  But I don’t really think it’s about the definitions anyway.  I think it’s about identifying, clarifying, understanding, and discussing the concepts that underlie the definitions.

At the end of the day, I think that a clear picture of what architecture styles are, and how they relate to architecture formulation, is extremely important for all practicing architects.  If you are skeptical, take a few minutes to read my article at and leave a comment to let me know if you agree or disagree.

December 7, 2008

Revised: Requirements vs. Architecture

Filed under: architecture,requirements,software architecture — charliealfred @ 9:41 am

Thanks to some spot-on comments by a colleague, Ruth Malan of Bredemeyer Software, I have made some revisions to the Requirements vs. Architecture page (, added last week.  The content of the article has remained pretty much the same as it was, but the the organization has been changed a bit.  The previous article had three themes:

  • how should requirements and architecture relate
  • what happens if you try to specify requirements without architecture
  • what you might try to do if you find yourself in an organization that doesn’t value the role of architecture in requirements

The original article didn’t juggle these themes as well as it could, and didn’t tie them together into a single coherent conclusion.  My hope is that the few small changes new organization makes improvments in this area.

November 30, 2008

New article on Requirements and Architecture

Filed under: Uncategorized — charliealfred @ 6:14 pm

A member of an Internet software architecture group I belong to posted a question the other day.  His current organization is leaning toward separating requirements specification and architecture, in effect, removing the software architect’s voice from the requirements definition process.

While there are several reasons that people in an organization might follow that path, none of them further the success of the system being built.  While I consider myself to be an experienced driver, I don’t consider me to be qualified to lead the requirements definition of the next generation Lexus.  While I recognize good accelleration, handling, and braking when I see it, I simply don’t know enough about fuel injection, compression, engine electronics, suspension, fuel economy, cooling, or any of the dozens of concerns that separate one car from another.  No.  This subject is too complex not to be left to the experts.

Yet, stakeholders of other systems feel empowered to take control of the requirements definition process, feeling as though once the essential “what” decisions have been made, they can safely lob the requirements specification over the wall to the engineers, who will somehow figure out “how” to do it.

This article explores the relationship between requirements and architecture, and illustrates the paradox of how some requirements must driver architecture while others must be subordinate to it.

November 24, 2008

Complexity-Driven #4 article posted

Filed under: Uncategorized — charliealfred @ 9:55 pm

Well, it took a bit longer than I thought, but the 4th article in the “Complexity-Driven Development” series has been posted.

This article ( applies the Complexity-Driven process to software architecture to a system that automates the routing, scheduling, and dispatching of drivers in a local area operation.  In addition, the example shows how the process can be applied to a product family architecture problem, as we consider three different types of pickup/delivery operation:

    o  LTL (Less than TruckLoad) – specializing in handling shipments ranging from 500-10,000 pounds

    o  Overnight Parcel – specializing in handling documents and small parcels typically under 150 pounds

    o  Private Fleet – specializing in making deliveries of a firm’s products to its customers.  Examples include bottled water delivery, resturaunt food service, uniform dry cleaning, and beverage distribution

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