Contrary to popular belief, agile development teams do in fact model and yes, they even do some up front requirements and architecture modeling. Two of the best practices of Agile Modeling are Requirements Envisioning
and Architecture Envisioning
where you spend a bit of time at the beginning of the project doing enough initial modeling to get you going in the right direction. The strategy is to take advantage of modeling, which is to communicate and think things through without taking on the risks associated with detailed specifications written early in the lifecycle
. In this blog posting I will focus on requirements envisioning, in a future posting I'll cover architecture envisioning.
The goal of initial requirements envisioning is to identify the scope of your effort. You need to do just enough modeling early in the project to come to stakeholder concurrence and answer questions such as what you're going to build, roughly how long it's going to take (give a range), and roughly how much it's likely to cost (once again, give a range). If you can get the right people together in the room, which can sometimes be a logistics challenge but not one that you couldn't choose to overcome, there are very few systems (I suspect less than 5%) that you couldn't initially scope out in a few days or a week. I also suspect that most of the remaining systems could be scoped out with less than 2 weeks of modeling, and if not then I'd take that as an indication that you're taking on too large of a project. I'm not saying that you'll be able to create big detailed specifications during this period, and quite frankly given the problems associated with "Big Requirements Up Front (BRUF)
" you really don't want to, but I am saying that you could gain a pretty good understanding of what you need to do. The details, which you'll eventually need, can be elicited throughout the lifecycle when you actually need the information. A common saying in the agile community is that requirements analysis is so important for us that we do it every single day, not just during an initial phase. I'll discuss just in time (JIT) approaches to requirements modeling in a future posting.
To envision the requirements for a business application, you might want to consider creating the following models:
- High-level use cases (or user stories). The most detail that I would capture right now would be point form notes for some of the more complex use cases, but the majority just might have a name. The details are best captured on a just-in-time (JIT) basis during construction.
- User interface flow diagram. This provides an overview of screens and reports and how they're inter-related. You just need the major screens and reports for now.
- User interface sketches. You'll likely want to sketch out a few of the critical screens and reports to give your stakeholders a good gut feeling that you understand what they need. Sketches, not detailed screen specifications, are what's needed at this point in time.
- Domain model. A high-level domain model, perhaps using UML or a data modeling notation, which shows major business entities and the relationships between them, can also be incredibly valuable. Listing responsibilities, both data attributes and behaviors, can be left until later iterations.
- Process diagrams. A high-level process diagram, plus a few diagrams overviewing some of the critical processes, are likely needed to understand the business flow.
- Use-case diagram. Instead of a high-level process diagram you might want to do a high-level use case diagram instead. This is a matter of preference, I likely wouldn't do both.
- Glossary definitions. You might want to start identify key business terms now, although I wouldn't put much effort into settling on exact definitions. I've seen too many teams run aground on "analysis paralysis" because they try to define exact terminology before moving forward. Don't fall into this trap.
For small teams simple tools such as whiteboards and paper are usually sufficient for requirements envisioning. But what happens at scale? What if you're working on a large agile team, say of 50 people, 200 people (IBM has delivered software into the marketplace with agile teams of this size), or even 500 people (IBM currently has teams of this size applying agile techniques)? What if your team is distributed? Even if you have people working on different floors of the same building, let alone working from home or working in different cities or countries, then you're distributed (see my postings about distributed agile development
). Suddenly whiteboards and paper-based tools (index cards, sticky notes, ...) aren't sufficient. You're still likely to use these sorts of tools in modeling sessions with stakeholders, but because of one or more scaling factors you need to capture your requirements models electronically.
In January Theresa Kratschmer and I gave a webcast entitled Agile Requirements: Collaborative, Contextual, and Correct
which overviewed agile approaches to requirements elicitation and management, including requirements envisioning. We also showed how Rational Requirements Composer (RRC)
can be used to electronically capture critical requirements information, enabling you to address the needs of large and/or distributed agile teams, while still remaining lightweight and flexible. I suspect that you'll find the webcast to be very illuminating and RRC something that you want to take a look at (the link leads to a trial version). Of course RRC can be used in other situations as well, but that's not what I'm focused on right now.
Teams which find themselves in regulatory environments will likely need to do more than just use RRC, as might very large teams. Regulatory compliance often requires more complex requirements documentation, which in turn requires more sophisticated tools such as DOORS or Requisite Pro, and I would consider using those tools in the types of situations that warrant it. One of the things that people often struggle to understand about agile approaches is that you need to tailor your strategy to reflect the situation at handle. One process size does not fit all, so you will end up using different tools and creating different artifacts to different extents in different situations. Repeatable results, not repeatable processes
, is the rule of the day. Further reading:
When adopting agile software development
techniques across a large number of teams within your organization it is important to provide a definition for what agile software development is, in addition to criteria
for what it means to be agile. Many people will point to the four values of the Agile Manifesto
and claim that's a good definition. Well... it might be a good definition for the visionaries and early adopters among us, but for people on the right-hand side of the technology adoption chasm (the early majority, late majority and the laggards) this isn't enough. Don't get me wrong, I'm a firm believer in the agile values but I like to cast them as philosophies instead of as a definition.
At IBM Software Group, the definition of disciplined agile software delivery which we have been sharing with our customers is:Disciplined agile software delivery is an evolutionary (iterative and incremental) approach to delivery which regularly produces high quality software in a cost effective and timely manner. It is performed in a highly collaborative and self-organizing manner, with active stakeholder participation to ensure that the team understand and addresses the changing needs of its stakeholders. Disciplined agile delivery teams provide repeatable results by adopting just the right amount of ceremony for the situation which they face.
I think that this is a pretty good definition, although I have no doubt that we'll evolve it over time.
I also suspect that the agile community will never settle on a common definition for what agile is and more than likely are smart enough not to even try. ;-)Further reading:
I've been getting a lot of questions lately about applying the acceleration metric
in practice. So, here's some answers to frequently asked questions:
1. How do I monetize acceleration?
This is fairly straightforward to do. For example, assume your acceleration is 0.007 (0.7%), there are five people on the team, your annual burdened cost per person is $150,000, and you have two week iterations. All these numbers are made up, but you know how to calculate acceleration now and IT management had darn well better know the average burdened cost (salary plus overhead) of their staff. So, per iteration the average burdened cost per person must be $150,000/26 = $5,770. Productivity improvement per iteration for this team must be $5,770 * 5 * .007 = $202. If the acceleration stayed constant at 0.7% the overall productivity improvement for the year would be (1.007)^26 (assuming the team works all 52 weeks of the year) which would be 1.198 or 19.8%. This would be a savings of $148,500 (pretty much the equivalent of one new person). Of course a 20% productivity increase over an entire year is a really aggressive improvement, regardless of some of the claims made by the agile snake oil salesman out there, although at 10-15% increase is a reasonable expectation. What I'd really want to do is calculate the acceleration for the year by comparing the velocity from the beginning of the year to the end of the year (in Western cultures I'd want to avoid comparing iterations near to the holidays). So, if the team velocity the first week of February 2008 was 20 points, now the same team's velocity the first week of February 2009 was 23 points, that's an acceleration of (23-20)/20 = 15% over a one year period, for a savings of $112,500.
2. Is acceleration really unitless?
For the sake of comparison it is. The "units" are % change in points per iteration, or % change in points per time period depending on the way that you want to look at it. Because it's a percentage I can easily monetize it, as you see above, and use it as a basis of comparison.
3. How do I convince teams to share their data?
This can be difficult. Because acceleration is easy to calculate for agile teams, and because it's easy to use to compare teams (my team has .7% acceleration whereas other teams down the hall from mine have accelerations of .3% and -.2% of teams), people are concerned that this metric will be used against them. OK, to be fair, my team might be OK with this. ;-) Seriously though, this is a valid fear that will only be addressed by an effective governance program
based on enablement, collaboration, and trust instead of the traditional command-and-control approach. Management's track record regarding how they've used measurements in the past, and how they've governed in general, have a great effect on people's willingness to trust them with new metrics such as acceleration. The implication is that you need to build up trust, something that could take years if it's possible at all.
4. Why does this work for agile teams?
Agile teams are self organizing, and an implication of that is that they will be held accountable for their estimates. Because of this accountability, and because velocity is a vital input into their planning and estimation efforts, agile teams are motivated to calculate their velocity accurately and to track it over time. Because they're eager to get their velocity right, and because acceleration is based on velocity, there's an exceptionally good chance that it's accurate.
5. What about function points or similar productivity measures?
Function points can be calculated for projects being developed via an agile approach, or other approaches for that matter, but it's a very expensive endeavor compared to calculating acceleration (which is essentially free) and likely will be seen as a bureaucratic overhead by the development team. My rule of thumb is that if you're not being explicitly paid to count function points (for example the US DoD will often pay contracting companies to create estimates based on function point counts) then I wouldn't bother with them.
6. What about calculating acceleration for iterative project teams?
Iterative project teams, perhaps following Rational Unified Process (RUP)
, can choose to calculate and track their velocity and thereby their acceleration. The key is to allow the team to be self organizing and accountable for their estimates, which in turn motivates them to get their velocity right just like agile teams (RUP can be as agile as you want to make it, don't let anyone tell you differently).
7. What about calculating acceleration for traditional project teams?
In theory this should work, in practice it is incredibly unlikely. Traditional teams don't work in iterations where working software is produced on a regular basis, they're typically not self organizing, and therefore there really isn't any motivate to calculate velocity (even if they do, there is little motivation to get it right). Without knowing the velocity you can't calculate acceleration. If you can't trust the velocity estimate, and I certainly wouldn't trust a traditional team's velocity estimate, then you can't trust your acceleration calculation. So, my fall back position to calculate productivity improvement would be to do something like function point counting (which is expensive and difficult to compare between teams due to different fudge factors used by different FP counters) and then looking at change in FPs delivered over time.
8. How can I apply this across a department?
It is fairly straightforward to roll up the acceleration of project teams into an overall acceleration measure for a portfolio of teams simply by taking a weighted average based on team size. However, this is only applicable to teams that are in a position to report an accurate acceleration (the agile and iterative teams) and of course are willing to do so.
9. What does a negative acceleration tell me?
If the acceleration is negative then productivity on the team is going down, likely an indicator of quality and/or team work problems. However, you don't want to manage by the numbers so you should talk to the team to see what's actually going on.
10. What does a zero acceleration tell me?
This is an indication that the team's productivity is not increasing, and that perhaps they should consider doing retrospectives at the end of each iteration and then acting on the results from those retrospectives. Better yet they can "dial up" their process improvement efforts by adopting something along the lines of IBM Rational Self Check
As part of the Agile/Jazz event In Milwaukee on the 29th I'll be giving a talk about the realities of agile software development. The URL for the event is http://www.iconatg.com/lp/events/jazz/jazz_milwaukee.html and I hope to see you there.
- Scott[Read More
Although it might not be obvious, and important success factor in adopting agile techniques
is to be able to determine whether a team is agile or not. The challenge that many organizations face is that many teams will claim to be agile, yet management, who often has little or no experience with agile approaches, cannot tell which claims are true and which are over zealous (I'm being polite). The following are the criteria that I suggest you look for in a disciplined agile team:1. Produce working software on a regular basis
. This is one of the 12 principles behind the Agile Manifesto
, and in my experience is a critical differentiator between the teams that are agile and those that are merely claiming it. Ideally the team should produce potentially shippable software each iteration. That doesn't mean that they'll deploy the system into production, or the marketplace, each iteration but they could if required to do so. Typically the team will deploy into a pre-production testing environment or a demo enviroment at the end of each iteration (or more often for that matter).2. Do continuous regression testing, and better yet take a Test-Driven Development (TDD) approach
. Agile developers test their work to the best of their ability, minimally doing developer regression testing via a continuous integration (CI) strategy
and better yet do developer-level TDD
. This approach enables development teams to find defects early, thereby reducing the average cost of addressing the defects, it also helps them to deliver higher quality code and to move forward safely when adding or changing functionality.3. Work closely with their stakeholders, ideally on a daily basis
. A common practice of agile teams is to have an on-site customer or product owner who prioritizes requirements and provides information on a timely manner to the team. Disciplined agile teams take it one step further and follow the practice active stakeholder participation
where the stakeholders get actively involved with modeling and sometimes even development.4. Are self-organizing within a governance framework
. Agile teams are self-organizing, which means that the people doing the work determines how the work will be done, they're not told by a manager who may not even be directly involved with the work how it will be done. In other words the team does its own planning, including scheduling and estimation. Disciplined agile teams are self governing within an effective governance framework
.5. Regularly reflect on how they work together and then act to improve on their findings
. Most agile teams hold a short meeting at the end of each iteration to reflect upon how well things are working and how they could potentially improve the way that they are working together. Sometimes this is done in a more formalized manner in the form of a retrospective
, but often it's done informally. The team then acts on one or more of their suggested improvements the next iteration. Disciplined agile teams take this one step further and measure their software process improvement (SPI) progress over time: the act of taking these measures, perhaps via a product such as Rational Self Check
, helps to keep the team on track in their SPI efforts.
I have yet to discover an ad-hoc development team which met all five criteria, and most of them rarely meet two or three.Further reading:
And now for some blatant advertising. ;-)
I just wanted to point out our agile development
page to you as it contains links to a lot of interesting agile resources produced by the folks here at Rational. There's links to white paper, recorded web casts, and Rational's Agility@Scale poster. Short story is that the page is worth checking out.
- Scott[Read More
Again and again I've seen IT organizations suffering from what I call the "Bureaucracy is Discipline" antipattern. For example, filling out forms and reviewing documents are both bureaucratic activities, neither of which require significant skill nor discipline to accomplish. However, agile practices such as developing potentially shippable software every iteration is easy to say but requires great discipline to accomplish. Respecting the decisions of your stakeholders, particularly those pertaining to requirements prioritization, is easy to talk about but proves to require great discipline in practice (particularly when you don't agree with a decision). It's easy to talk about taking a test-driven approach to development
, but in practice it requires significant skill and discipline to actually do.
A "process smell" which indicates that your organization is suffering from this antipattern is a focus on following repeatable processes instead of focusing on repeatable results. An example of repeatable processes is following the same route to work every day regardless of driving conditions. An example of repeatable results is getting to work on time every day, but being willing to change your route as required, bicycling into work instead of driving, taking public transit, and so on. Nobody really cares how you get to work each day (the process), what they really care about is that you got to work on time (the result). Sadly, we've been told for decades now that repeatable processes are critical to our success in IT, yet when you step back and think about that's really a reflection of a bureaucratic approach. On the other hand, a focus on repeatable results is a reflection of a more disciplined approach. Interestingly, the DDJ 2008 Process Framework survey
found that given the choice that people would much rather have repeatable results over repeatable processes
when it comes to IT.
Mistaking bureaucracy for discipline, or rigour if you prefer that term, is a reflection of the cultural damage that has occurred over the years in IT organizations as the result of traditional philosophies and techniques. Unfortunately, this mistaken belief is a significant inhibitor to software process improvement (SPI) efforts, in particular agile adoption efforts
, which must be addressed if you're to be successful. Overcoming this challenge will require a significant cultural shift in some organizations, and many people (particularly the bureaucrats) will find this uncomfortable.Further reading:
I'd like to leave you with this parting thought: Bureaucracy is bureaucracy and discipline is discipline, please don't confuse the two
I'm often asked by customers for case studies of successful agile adoptions or agile projects in general. This is definitely a valid request, and yes, such case studies exist. But I'm often concerned that the people making these requests don't appreciate the implications of what they're asking for. My concerns with case studies are:
- The juicy information is rarely included. The information that you really want to find out, such as what went wrong and why it went wrong, is rarely discussed. If problems, oops I mean "challenges", are discussed at all they're typically glossed over in favor of focusing in on the positives. Although many people want to write up the juicy bits this information is invariably edited out through the company's vetting process. In short, my advice is to take case studies with a grain of salt.
- Some case studies are more fiction than fact. Although this isn't a problem with IBM case studies due to the governance efforts of my good friends in IBM's legal department (we love you folks, really) it can be an issue with some case studies.
- The case study may no longer be true today. Stuff happens. Perhaps the case study was mostly true at the time it was written, but now that time has passed problems have appeared that weren't apparent earlier, thus the effort wasn't as nearly as successful as it was written up. For example, a few years ago I ran into the manager of a team that I had read about in one case study, only to find out that once the study was published the key team members left the company to become consultants in that subject area. Having lost these people, who were all very highly skilled, his system proved to be unmaintainable by the rest of his staff who weren't so highly skilled and had to be rewritten. Over time the success story turned into an abject failure.
- Waiting for case studies puts you in the position of follower. For every case study that gets written, dozens, if not hundreds of similar efforts didn't get written up. Writing case studies is hard, takes time, and the writer seldom gets much benefit from doing so. The lag time between the project completing and the case study being published can be many, many months and sometimes years. The implication is that by the time you wait for several case studies that are similar to your situation you've pretty much lost all opportunity for competitive advantage and are now merely trying to catch up to the organizations who are clearly ahead of you (the writers of the case studies).
- What has the requester given back to the community? I often hear people lament that there isn't enough case studies, or isn't something close enough to their situation. Yet, when I ask them how many case studies they've written and the answer is usually none. If you want to get you also need to give. ;-)
So, next time you think you need a case study before making a decision, recognize that you may be paying a fairly high opportunity cost for information that is questionable at best.Further reading:
I'm happy to announce Rational's Agility at Scale poster which is currently available free of charge from the Rational poster order page
Although I'm obviously biased as I was involved with its creation, the poster includes some really good information about how to scale agile software development practices effectively. It summarizes the scaling factors, such as large teams, distribution, regulatory compliance, application complexity, and so on that you should be concerned with. It also presents a full agile software development lifecycle that goes beyond the construction focused lifecycles of common "agile in the small" processes. It also summarizes the practices of lean development governance, giving you some insight into how to govern your IT environment more effectively.
I think it's a pretty good poster that's worth checking out. It's free, so it's hard to argue with the price. Most importantly, it would look pretty good hanging on your office wall.
A common misunderstanding about agile software development approaches are that they're only applicable to small, co-located teams. Yes, it's much easier to be successful with small teams, and with co-located teams, and as a result agilists being smart people prefer to work this way. After all, why take on extra risk when you don't need to do so? But, sometimes reality gets in the way and you find yourself in a situation where you need a large team, or you need to distribute your team (see previous blog postings for strategies for distributed agile development), and you would still like to be as agile as possible. The good news is that it's still possible to be agile with a large team, although you will need to go beyond some of the popular "agile in the small" strategies to succeed.
Here are some disciplined agile strategies to succeed at large-team agile:
- Question the need for a large team. Many times an organization will believe that they need a large team because their process is overly complex, because they're still organized for waterfall development, or simply because that's what they're used to. I've seen teams of 80 people doing the work of 20 as the result of over-specialization of job roles and all the bureaucracy required to organize and validate their work.
- Do some initial envisioning. In order to succeed the team must work together towards the same goals. This is true for small teams but doubly true for larger ones -- without a common vision chaos will quickly ensue. You must gain this common vision on two fronts: you need a common business vision and a common technical vision. To gain the common business vision you must do some initial, high-level requirements envisioning and to gain the common technical vision some common architecture envisioning. This isn't to say that you need to take on the risk of detailed, up-front specifications but you must at least have a high-level understanding of the scope and technical solution in order to move forward effectively. So, expect to spend the first few weeks of your project doing this initial modeling.
- Divide and conquer. You never have a team of 200 people, instead you have a collection of subteams that add up to 200 people. This is called having a team of teams.
- Align team structure with architecture. The most effective way to organize the subteams is to have each one implement one or more components, and thereby to build your overall system as a "system of systems". This reduces the coordination required because the majority of the communication will be within the subteams themselves. You'll still need to coordinate the subteams, that will never go away, but you can reduce the overhead (and the risk) by being smart about the way that you organize the people. A common mistake is to organize around job function (e.g. having architects in Toronto, developers in Raleigh, testers in Bangalore, and so on). This increases communication overhead and risk because these people need to work together closely to get something built.
- Project management coordination. Each subteam will have a team lead/coach, and these people will need to coordinate their work. There is often an overall project manager who leads this group. To coordinate the work within their subteam the team lead/coach will often have a daily meeting, in the Scrum method this is called a scrum meeting, where people share their current status and identify any problems they may be running into. To scale this effectively the team lead/coach attends a daily team coordination meeting, a scrum of scrums, where the same sort of information is shared at the overall team level.
- Product owner coordination. Similarly, each subteam has a product ownder, also referred to as an "on-site customer", who is responsible for making decisions about the requirements and for providing information to the team in a timely manner. Sometimes a single product owner will work with several subteams. The product owners will get together at the beginning of the project to do some requirements envisioning to identify the initial scope and to start portioning the requirements between the subteams. Because the requirements between the subsystems are interrelated and should be reasonably consistent, the product owners will need to meet on a regular basis to share information, to negotiate priorities, and to resolve requirements-related disputes.
- Architecture coordination. Each subteam will have an architecture owner, often a senior technical person and sometimes also in the role of the team lead/coach. These architecture owners will get together at the beginning of the project to do some initial architecture envisioning, based on the requirements envisioning efforts of the product owners. They will identify the major subsystems, and their interfaces, enabling the effective organization of the team into smaller subteams corresponding to the architecture. They will also get together regularly to evolve the architecture and to resolve any major technical issues.
- System integration team. For complex systems, which is often what large teams work on, an effective system integration effort is critical to your success. Although this may be easy at first, as the overall system evolves the need for a subteam focused solely on this quickly becomes apparent. This not only supports the development efforts of the subteams, it also supports independent investigative testing.
- Independent testing team. An independent testing team is common on mid-to-large size agile projects to enhance the testing efforts of the development subteams. This testing team will work in parallel to the developers, they get a new build on a regular basis (minimally each iteration, although more often is desirable), which they test in more advanced ways than what is typical with Test-Driven Development (TDD). For example, they often validate non-functional, quality of service (QoS) type requirements as well as technical constraints, things that often aren't captured well via user stories. They'll also do investigative testing to try to break the system by using it in ways not thought of by the product owners.
- Some specialties reappear. On larger teams it can make sense to have some people be a bit more specialized than what we normally see on small agile teams. For example, it's common to see people in the role of agile DBA, tech writer, build master, or user experience (UE) professional. More complex systems often require people in these roles, although it still behooves these poeple to not be pure specialists but instead to be generalizing specialists with a wider range of skills. Also, recognize that the reintroduction of specialists can be a slippery slope back to the bureaucracy of traditional software development.