Too Much Focus on the Beginning of Software Lifecycle?

rfreedman asks: "Most of the buzz on the web about software development tools, languages, and practices seems to concentrate on getting software developed as quickly as possible. Take, for example, the current huge hype about Ruby on Rails, and how it allows the creation of a CRUD web-database application x-times more quickly than every other environment. It seems to me that this concentration on initial construction of software ignores the issue of total cost of ownership. Most people who develop software also have to maintain it, and have to support changes to it over long periods of time. As has been discussed many times over the years, maintenance is the most expensive part of the software development life-cycle. I think that the software development community would be better served by discussions of how to build more robust, flexible, and maintainable software (thereby driving down TCO), than by the endless discussions that we currently see about how to build it quickly. What do you think?"

Comments

Good point

[Duhavid]

Now, how to convince the PHB's and the bean counters?

Re:Good point

[Spectra72]

It's not like programmers just love to dive into maintaining code either you know. They're usually the ones just chomping at the bit to chuck everything and start something new and exciting to put on their resume (or blog about these days).

Justified

[Umbral Blot]

The emphasis on fast devlopment is justified, at least from a business perspective, because first to market gives a huge advantage in software, not to mention the network effect. Sure the ability to maintain and upgrade software is somewhat important, but it doesn't matter so much if it takes a long time if you are already dominating the market. Similiarily start-ups don't care about these issues since they plan on being bought out before they matter. Yes these attitudes create serious problems and lead to poorly made software, but what can you do about it? (besides using open source)

Re:Justified

[humblecoder]

Actually, being first to market really isn't that big of a deal. There are tons of products which were first to market which have slided away into oblivion because they were rushed out the door. Because they were rushed, they ended up sucking the big one. Then, another company comes out with a better, more polished version of the same product and everyone forgets about the first, sucky product.

The dotcom bust is littered with companies whose business model was, "be first or else", and nobody seems to remember them.

Re:Justified

[msezell]

If you take a closer look at many of the platforms that are hot right now you will notice that the concepts that give them the ability to quickly create well designed websites also make much easier to maintain these sites. With standardization and the use of modular construction, or what some call tiered programming, you have separated the logical processes and are able to change any one part without having to reinvent the entire website. When you need to rewrite the script calls to the backend, you don't have to worry about what the output of the data will look like in the front end because they are two separate processes that hand off data to their suspected components. Think of it like Cascading Style Sheets, one change to the file and all pages using that definition are changed in on fell swoop. This has a major impact on TCO when changes can be address in a single place that will impact across the whole site.

Re:Justified

[jbertling1960]

These attitudes are perhaps justified in a commercial software environment, but I have seen the same trends in corporate IT departments at previous employers. I have found that the progression runs like this: 1. The IT effort becomes increasingly politicized. 2. Old guard IT managers are replaced by political appointees who have no real IT experience. 3. These new managers lack the experience and insight (and often the maturity) to measure the real level of progress in software development and, because they feel that they must have something to measure, schedule becomes the only measurement. When I began writing software professionally in 1985 (Yes, I am ancient), it was pretty well recognized that a schedule was a tool by which you measured your progress toward a predefined goal. Now days, the schedule is the goal. So because people tend to perform toward there goals, we get schedule. What we don't get is quality, sustainability, customer satisfaction, etc. Also, as an added bonus, we get developer burn-out, high turnover rates, and an us-versus-them mentality between corporate IT and their customers in the business groups that have to use the steaming pile systems produced by these attitudes.

i think you answered your own question

[moochfish]

I'm pretty sure a big part of why these frameworks are popular come from the fact that they allow for smarter, fewer lines of code, ultimately making maintenance easier. Much of the lower level problems like database connectivity, optimization, resource management, etc. are handled by these frameworks and other higher level languages which in turn allow the developers to focus on the business logic, rather than debugging their latest build of the database.

At least that's why I assumed rapid developement frameworks caught on.

Re:i think you answered your own question

[Anonymous Coward]

As Douglass Adams said: the problem with things that can't possibly go wrong is that when they do go wrong, there's no way to fix them. When you accept the "easy" models promoted by some of the higher level languages, you might take the framework your using as far as it goes and realize that it doesn't go far enough. At that point you're stuck. For example, you may have written a powerhouse GUI application for a platform like .NET or Java and now that you've invested millions in development, you realize that there's nothing more you can do to optimize performance on that platform: your application is a memory hog and takes forever to load. It's still a good application, but your choice of development tools has put a hard limit on how far you can go. That's a tough spot to be in.

Re:i think you answered your own question

[skiflyer]

At least that's why I assumed rapid developement frameworks caught on.

There's also the fact that in many jobs a huge percentage of programs are run once, or maybe run once a day for a month... and maintainability isn't an issue. My previous employment was just that, lots of tasks that needed to be scripted, and then they were done. Occasionally a program become popular and had to be scaled up to repeated use, and then we did just that. But the rapid development was great for the ones that didn't, sometimes the code for them was garbage, but worked, and sometimes it was really well organized and easy to transform... but more importantly the tasks where completed in less total hours (programming + running) than if a human had to process the issues by hand.

Now, as someone who's a boss and cares alot about the dollars per hour, one of my constant frustrations is watching someone write a script for a run once application that takes 3 hours to write and debug, 5 seconds to run... while I'm paying them $30/hr, whereas they (or a better yet a $7.50/hr employee) could've done it by hand in 30 minutes.

No.

[hsmith]

You have large maintnence costs because no one properly plans up front for the long term. People want to see something and they want to see something fast. No one sits down to write the proper documents, no one sits down to plan ahead, they think for the short term only. Which leads to long term problems down the road. At least, that is what I see as major issues on things i have worked on.

people don't want to make the initial investment to plan ahead, so they end up spending much more in development costs because no one decided where the product should go.

Re:No.

[RingDev]

Here! Here!

The problem isn't high level languages or agile development. The problem is a lack of foresight, planning, and documentation.

We have two major systems at the company I work for. One, that the related staff spent 2 years documenting their business practices and exactly what they wanted the application to do. They took that huge document to a couple of consulting companies and said "we want this." 2 years later the consulting company that won the bid turned over a nearly perfect application.

The other app is an extension of a 3rd party application. This app started development with little to no documentation, no project manager, and no one who had actually worked with the 3rd party application. Flying blind into a short deadline has left us playing redevelopment games for almost 2 years! We finally managed to get the critical personnel together to get the system and processes documented, and after 3 months of business process documentation we should be set to re-write the business layer of the application in 6 months.

Had the user group worked with the 3rd party app prior to launch, and documented their processes, the entire application could have been developed in under 9 months. But with out that work on the front side we will have over two and a half years wrapped up in development from 3 people.

One more project like this, and I'm moving to management. As much as I love coding, I hate inept managers even more.

-Rick

Re:No.

[Kadin2048]

That's a great anecdote, and I don't think that you can hit that point hard enough.

If somebody came to you and said "hey, I've got this great new way to build a bridge! Instead of making up plans, we'll just start building it! We'll build it out of popsicle sticks first, and then we'll go in and add some steel beams, and toss some pavement on top of that," you'd say they were insane. Nobody does stuff like that in the real world -- yet that's exactly what a lot of poorly-managed 'agile' software projects are doing. They're getting short-term prototyping gains but at the cost of maintainability and probably stability as well.

Rather than figuring anything out ahead of time -- actually answering the hard questions like "what do we want this software to do and how do we want to do it?" they just start making something. It's like just giving some steelworkers a pile of rebar on either side of the river and telling them to build towards the center and figure the details out later.

I think one of the biggest problems in software development, and it's really endemic, is an underappreciation of the pre-development work: requirements analysis, specification development, even simple stuff like the clear division of job roles and responsibilities. If you get that stuff done, the actual coding ought to be an academic exercise, not a seat-of-the-pants experiment.

Part of the problem lies with managers who don't understand software, and just take any opportunity to compress schedules and make themselves look better, and another problem is with "programmer culture," where people think the ideal way to solve a complicated problem is just to put a half-dozen developers in a room for a weekend with a few gallons of Mountain Dew, an Amex card, and the number of the nearest Domino's Pizza. (Although to be fair, this attitude seems to be less common among developers who have SOs/families, or are used to 40-hour workweeks.)

While concentrating on "getting it out the door" may solve the problem in the short run, it's almost certainly not going to give you neat, easily-maintainable, well-documented code. And when you're looking at the long-term maintainance costs, it sometimes can be better to not have anything at all, than to have a lot of spaghetti code that somebody is just going to have to rewrite down the road, when they can't figure it all out.

Re:No.

[mcrbids]

If somebody came to you and said "hey, I've got this great new way to build a bridge! Instead of making up plans, we'll just start building it! We'll build it out of popsicle sticks first, and then we'll go in and add some steel beams, and toss some pavement on top of that," you'd say they were insane. Nobody does stuff like that in the real world -- yet that's exactly what a lot of poorly-managed 'agile' software projects are doing. They're getting short-term prototyping gains but at the cost of maintainability and probably stability as well.


A complex software project doesn't compare well to a bridge. It's more like a city. Nobody goes and says "Let's build a city!", lays out plans, prototypes and discusses what business go where.

That's just stupid; nobody does a city like that.

A bridge is a simple item, an artifact of intelligence, it's an item with almsot irreducible complexity. A city, however, is a highly complex, interactive social organism with bazillions of interactions, many of which you can't easily forsee. It has a very small level of irreducible complexity. Lots of software has much in common with this.

Cities ARE built in a "agile development" fashion. People spec out just enough to get started, to get them by for the next few months/years, slam together a some houses, and maybe a store or two. People like living there, then somebody comes along and thinks "We outta have.... a Newspaper!" and they build a building and buy paper and start writing articles and printing and all that jazz. It's a little different than software because most software has a lifespan of perhaps 10-20 years, cities have lifespans in the hundreds of years.

Changes in this city are incremental; they're small. They happen everyday. Somebody does an extension on their house. The lady down the street gives birth to a son. The corner grocery starts selling sandwiches. The empty lot down the street becomes a movie theatre. And so, the agile development model continues.

You're dead wrong - the bridge is a small, incremental example of EXACTLY how well-done agile software develops!

It's a disposable culture.

[aussersterne]

Maintenance? If you can lower the cost of creation enough, it's cheaper to just start from scratch every couple of years. It's the same phenomenon seen in blenders and automobiles. Send it to the landfill and get a new one made.

This phenomenon is only bound to accelerate as software labor costs go through the floor due to offshoring.

Re:It's a disposable culture.

[wtansill]

Maintenance? If you can lower the cost of creation enough, it's cheaper to just start from scratch every couple of years. It's the same phenomenon seen in blenders and automobiles.

Ehhhhh -- no. Maybe some trivial applicationm can be thrown away and reengineered every few years, but business generally does not have that luxury. There are data conversions to consider, as well as the fact that, depending on the system in question, an entire "ecosystem" has likely grown up around the core application. You cannot just throw the application away without ripping out and reworking all those other systems that depend on it in some form or fashion. Yes, I know -- Software as a Service to the rescue -- well defined interfaces between applications, etc. Except that in the main, that does not happen, so you are better off having an extensible, maintainable system. Now if I could only sell that idea to the PHB...

Re:It's a disposable culture.

[GigsVT]

Terrible idea. Happens a lot though. Not created here syndrome doesn't help.

My personal policy is that unless the requirements change radically, or you are facing serious obselence, you should never start over from scratch.

Even if you wind up rewriting 95% of the code, you'll prevent yourself from making the same mistakes that the original developer already sorted out.

It goes something like this:

You find a chunk code that looks entirely unnecessary.
You take it out, replacing it with the obvious solution.
You run your testing stuff, it's easy since you were starting from a working system, it's all regression testing.
You often find that the code actually did do something important, something subtle usually.
You rewrite it in a better way, that accomplishes the same thing.

The alternative, starting from scratch, means that you will likely miss the subtle need for that particular thing. You don't have the benefit from starting from something that works.

It seems like it would take longer, but it goes a long way to prevent requirements and their subtle implications from falling through the cracks. You basically have a cryptic book telling you all the little tricky things. If you throw that book away then you have to rediscover them yourself. And even if you keep it, you aren't going to seriously read it in a deep way if you are starting over completely. By the time you understand all the old code fully you could have been rewriting it incrementally.

Re:It's a disposable culture.

[aauu]

The attitude you get when you hire children. Well designed apps are maintainable and last for much longer than the transient early career coders can believe. I have written application components that ran unchanged for more than a decade without any modification. Careful thought, proper design with comprehensive error detection and incremental testing during construction can produce an efficient proper solution that will stand the test of time. Enterprise applications often have lives of a decade or more. Banging out a new application in record time is useless if the design and construction is so shoddy that the application cannot be maintained without discarding the entire pile of crap for a new version. Notably, the high speed coders have moved on to new jobs so that they avoid responsibility for the mess they left behind. Maintenance is inevitable because time is change. I have spent 30 years in the IT industry and my experience that all but small new companies will have an application portfolio with an average age 7 years. This will be longer for core functionality as you do not re-engineer an enterprise in 90 days. When development can take 4 to 5 years and millions of dollars to replace a core application it is very important to consider the life of the application and platform. Most of the surviving dot coms now have 7 year old applications that are straining from the quick implementation that did not consider scalability and flexibility in the haste to get the company started initially. Maintenance also is much more difficult than coding a new application. It is much harder to extend the functionality of an existing production system without breaking anything. Real programmers can do maintenance successfully where others give up and want to discard all previous investments for their convenience.

You misunderstand rapid development

[TrappedByMyself]

The movement to develop "quick software" is not for the sake of developing something fast at the expense of other concerns. It is meant to address requirements problems, which are the life or death of an applciation.

It's rare for a customer to know what they want. Even worse, alot of development happens without customer involvement. For example, there is usually a huge early requirements meetings, then developers walk away and write code for 6 months. Sure there are demos in between, but they are usually heavily scripted to give the illusion of progress. At the end the developer shows up with a system and the customer wants to change about a bazillion changes.

So...the recent movements in agile or rapid or whatever you call it grew to address these issues. By getting up a functional prototype quickly, you get the customer usuefully involved early in the process. They can use the system and begin to get an idea of what they really want. If you chunk into 4 or 6 week cycles you can have continuous deliverables. And if you focus on everything such as testing, documentation, and deployment from the get go, you can have complete systems for each cycle so you always have demo ready versions. With frequent, complete releases the customers (and management) are much less worried about progress, which means less stress for the developers.

Somewhat idealistic, I know, but it works pretty well.

RAD not necessarily higher TCO

[TheSpoom]

For years I've been working with pure, vanilla PHP outside of any sort of buzzword framework. That's not to say that my code was unorganized (quite the opposite, I'm pretty anal when it comes to code clarity), just that I believed as the original poster did that MVC frameworks and the like weren't worth the time.

I've recently started experimenting with CakePHP, and it has somewhat changed my thinking on the matter.

A lot of things we tend to do, especially in web development, get repeated over and over. Data validation, SELECT statements and their JOINs, administration backends, login systems... I could go on. In my experience, it's been when I've been bored to death of doing something repetitively that errors would start to creep into my code. It's pure probability: the more you do something, the better chance you have of one of those things having something wrong with it.

RAD solutions posit a solution to this, centralizing all those repetitive things so you avoid having to type the same thing over and over, and thereby reducing the chance that there is an error in any one of those repeated things. If there's an error in the actual framework, one can fix it, ideally, in one location rather than throughout a script (though the frameworks themselves tend to be closely scrutinized to avoid any obvious issues).

I guess what I'm trying to say is that coding less can mean coding better, as long as you understand why you're coding less, and not doing it simply because you can.

I agree

[The OPTiCIAN]

> What do you think?

Spot on. It's funny to watch people do demonstrations of how quickly Ruby on Rails can be used to build something because it's exactly the same sort of thing that was used to promote WebObjects ten years ago and I know from experience what rubbish it is. For all but the most simplistic applications you have to abandon the mapping of form elements to the database because you need to do validation. If you start off with a RAD approach to problems to these pages and add validation as an afterthought they quickly degenerate into a horrible mess. There will be less of a problem in this respect with ruby on rails because the data layer is so primitive so there are some knots you can't even contemplate being tied into, but - um - what was the point of Ruby on Rails again? :)

I imagine that doing major schema refactors on Ruby on Rails apps would be a nightmare because there's no easy way to check that you've fixed all the breakages. Whereas if you use EOF or Cayenne and get a culture in your software where developers avoid using key-paths except in agreed spots it's quite easy - you make the change, fix the areas where you find compile problems and then its done.

Something I would be interested to see would be some sort of business logic layer that could emulate a JDBC adaptor. Then you could write your application against that and bind to it as though it were a schema, but in the background it would in fact have business logic behind it. This would allow a separation between business logic and presentation but still allow you to quickly bind applications up as you do in the RAD webapp tools.

Re:I agree

[Duhavid]

It's funny to watch people do demonstrations of how quickly Ruby on Rails can be used to build something

And it is also funny to have to take that demonstration code and turn
it into a production ready system. Time is never sufficient, because
management can only see the (poorly) implemented features, and not
the lack of error handling and return value checking, and robustness.

Re:I agree

[PintoPiman]

I'll agree with you that running off and adopting $FRAMEWORK as the Next Big Thing without first understanding the pros/cons/tradeoffs involved is haughty. HOWEVER...

It would appear that you have taken your elementary and incomplete understanding of RoR and created an assumption that RoR is elementary and incomplete.

Not only is does RoR support validation and testing, it practically forces them down your throat. After years of C++, Perl, Java and the like, I've never seen a framework that elevated unit testing to such a prominent level. One of the more famous of the 'demos' that you refer to is the creation of a weblog in 15 minutes. Within those 15 minutes, the author demonstrates the basic unit testing, validation and error handling code that RoR *does for you*. Scaffold, rake and 'validates_*' won't take you everywhere you need to go in order to be robust, but they sure do give you a hefty shove in the right direction.

Still, unit testing and input validation aren't even among the top benefits of RoR specifically, or the RAD scheme in general. The framework and the community that supports it actively guide developers in the direction of numerous other good habits. MVC and DRY are acronyms that every dev has heard and most have ignored, to the peril of their apps' maintainability. RoR encourages these techniques and demonstrates their effectiveness.

To be over-blunt about it, the point of RAD is that no matter how long you plan, you still might as well be going off half-cocked. Requirements tend to be ill-defined and rapidly evolving for most projects. RAD operates from the assumption that reducing the time between requirements collection and release gives you a better aproximation of the real-life requirements *at the time of release*. If you spend twice the time finalizing the spec and twice the time implementing it, you're just giving the requirements a head start - they will outrun you. What unit tests, MVC and DRY all have in common is that they combine to make refactoring as easy as possible, simplifying the development cycle and allowing for releases early and often.

No framework or project management scheme is a substitute for good coders and forethought, but if I had to choose a methodology for today's small-medium sized project, RAD/Agile would be it. You can have your waterfall, your SAP, your XML configuration files and your weeks of Requirements Analysis meetings with PHBs who don't have the perspective to know what they want until you've shown them what can be done.

Maybe the beginning gets too little attention ...

[richg74]

I think I might argue that the beginning of the development processs -- or, at least, what should be the beginning, namely the design, often gets too little attention. My experience leads me to believe that most gnarly maintenance problems stem from poor design more than from low-level coding blunders. Think of the well-publicized security issues that have bedeviled Microsoft. I don't think they occur because Microsoft has bad programmers, but I do think that the "tightly coupled" design of Windows is a mistake, and makes problems much more difficult to resolve.

One reason these tools get a lot of attention is that using them produces a measurable effect. It's the "bookkeeping fallacy": things that are easy to measure must be more important than things that are hard or impossible to measure.

I do think these rapid development tools can add a lot if they are used intelligently, which I think means using them to present concrete ideas and prototypes quickly, in order to gain understanding of the problem domain and to get user feedback. But I still think Fred Brooks's advice in The Mythical Man-Month is correct: plan to build the first version to throw away. You will in any case, and it's better not to deliver the rubbish to the customer.

The curse of IT has always been, "There's never time to do it right, but there's always time to do it over."

I think you got it backwards

[humblecoder]

I think the problem isn't that there is too MUCH focus on the beginning of the software lifecycle. The problem is that there is too LITTLE focus on the beginning of the software lifecycle.

The beginning of the software lifecycle is supposed to consist of analysis and design - both of which can lead to the construction of a superior product if done right. The issue is that many of these "quick start" languages and frameworks make is easy for a programmer to dive right into the coding phase without considering the overall design of the system. Thus, they skip the beginning steps in the software lifecycle.

Redwood Trees and Grasses

[hansreiser]

Each approach has a place in the ecosystem. Reiser4 could only have been developed the slow way, but that was because we were going into a mature market with solutions that worked already in place. We needed to architect for maintainability because we knew it was a long hard road ahead, and we weren't going to be quitting soon, so we made a plugin architecture.

The problem we have is when the grasses dis the trees and the trees dis the grasses. The Linux Kernel Community, and the rest of society, have too much of that going on.

Respect those who are nothing like you, and see that they have value to society that you cannot match but might complement.

Release early, release often!

[mcrbids]

We have two major systems at the company I work for. One, that the related staff spent 2 years documenting their business practices and exactly what they wanted the application to do. They took that huge document to a couple of consulting companies and said "we want this." 2 years later the consulting company that won the bid turned over a nearly perfect application.

Wow. Sounds like a ringing endorsement for planning and quality execution.

Unfortunately, though I've tried time and time again, I've never gotten anywhere near the participation required to lay out everything in advance accurately. Worse, the few times I've actually managed to get something together and gotten everybody to sign (in blood) in triplicate, it was rejected on the very first day of rollout because they didn't expect something that was, upon rollout, patently obvious. In my experience, people don't know what they want until they see that you have isn't it. Very few people have the intelligence and foresight to extrapolate what a screenshot will mean to them, in the real world.

So, I've turned my back on the whole idea, and have instead adopted a modified "agile development" approach.

I do just enough specifications to determine how all the pieces are going to fit together, what all the database fields are, and how the constraints, triggers, and foreign keys assure reasonably sound data. I beat the idea in front of a few people and search for objections, until most people approached seem to like the idea, and nobody has any major bones to pick.

Then we code - it goes out the door for public release as soon as it seems stable and workable. I don't bother trying to make it totally bug free, so QA is short and sweet. On rollout, I ask our clients to review it and inform us of any bugs. We never get it right the first time, and we're pretty up front about that. But we fix it quickly, and most importantly, we modify our software towards what the customer actually needs. Stuff that is simply not needed gets dropped pretty fast.

Our software is designed to "fail early" - so that inconsistent or inaccurate data doesn't hurt anything. And so far, we've had only minor issues in over 2 years of heavy, active, exponential growth and development.

Turnaround time for an average modification is less than a week. We issued over 40 releases in the last year alone. Every so often I go over everything in a new perspective, and do a bunch of minor tweaks all at once - that's when UI improvements come down hot and heavy.

The response has been wonderful! A customer who mentions an idea, and sees it implemented a few weeks later is your evangelist for life. You practically become their religeon, and you'll get recommendations and referrals for the rest of your days.

I've heard people talk about it like bargain hunting - they hunt around - just to see what's new!

So far removed from the bleak hopelessness so common here at Slashdot about software projects - it's exciting, intense, fun, and profitable!

Re:Release early, release often!

[nightowl03d]

In my experience, people don't know what they want until they see that you have isn't it.

You don't say what your target market is, so what I am going to reply here has a relatively small probability of applying to your situation. But this is slashdot so I don't have to worry about a silly think like relevance, so here we go....

If you had this experience, chances are the person who fell down on the job is not the user, the PM, or the developers, but the software architect for not identifying a fluxional feature. In fact the sole justification for the Agile methodologies is these fluxional features. Many, (but not all), "Agile" projects I have been called in to clean up have made this mistake. In most of these cases, the principal performing the architect role was a true technology wizard, but who would filter everything the business people said to conform to the principal's pre-conceived notions or more subtly falling into the "one true answer" trap.

When a contentious topic comes up in analysis meeting, a technology focused architect often seeks to resolve it and record the resolution, and hard-wire that behavior into the requirements. This is death. As this type of error multiplies, the seeds have been sown for disaster. What should have happened, was a contentious point should be used as an indicator of a volatile feature that should be designed with ease of customization in mind.

Volatile requirements are the norm and the identification of fluxional features is the key to knowing when to address them.

In my market these areas often require extreme flexibility.

1. Screen details, and screen workflow on the UI side. Keep the UI shell stupid using an MVC/MVP paradigm. (.Net 2.0 does a fairly good job with this if you use their binding framework judiciously, .Net 3.0 does a better job, JSP sucked donkey balls in this area, JFC and JSF are better, ROR is pretty good for simpler web sites). Oddly enough navigation is usually pretty stable once the stakeholder meetings have been conducted. Be ready for this.

2. New commands will be added. (Commands in this sense are persistence operations or new features). Work out early how all of those contentious points that came up in your continuous interviews with your stakeholders can be resolved with an appropriate plug in approach. What meta data will be needed for future commands? Be ready for this.

3. Your input formats and medium will change. Be ready for this.

4. Business rules will always change, never allow anything structural in your system be governed by any business rule stated in a stakeholder meeting. Keep them behavioral. Construct/purchase an appropriate rules engine who only knows about business rules. Be ready for this.

5. New persistence mechanisms will be desired. Be ready for this.

Sounds a lot like Agile doesn't it? The only difference is that be ready for this changes to react to this. Putting the effort in it to think about these and other volatile issues up front finds the trolls sooner, which enables refactoring efforts to be more local than they would have been otherwise. This list isn't comprehensive, so remember that outside of mathematics, and mathematical physics, there is almost never a one "One True Answer". My personal rule of thumb if that an issue can't be resolved via a thought experiment it should be made a fluxional point.

Very few people have the intelligence and foresight to extrapolate what a screenshot will mean to them, in the real world.

If you are using screen shots to walk through your scenarios, it is no surprise to me that you have gotten bad results. Paper prototypes will let the stakeholder see the consequences of their actions much easier. But that isn't enough either. You should also make efforts to communicate the state of the system and processes at each point in the screen shot. Designing a good walk through is more of an exercise in psychology than a technical exercise . Wal