James Oloo Onyango - Programming Insights

Mastery of this pervasive field of programming demands a life time's effort. It cannot be bought at a lesser price!

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Monday, March 11, 2013 #

Since the advent of Java (and the JVM) in 1995, we have seen a plethora of Web Development techniques. The general trend start from the lean methodologies to the era of the Enterprise Java Beans (EJBs) which were quickly seen to add unnecessary complexity and the to the thinner frameworks (Struts, JSFs etc). At any given time, Java, unlike its fierce conmpetitor .NET has always offered multiple frameworks to get the same job done, this has proved to be both an advantage and a disadvantage. However my current concern now is the introduction of different languages running on the JVM.

The shortages of Java as a language over the years have become much more apparent (i am guessing this might be because of the additional features in younger languages like C# and the introduction and improvements in Ruby, Python et al). However the work done on the JVM and the offerings right off the bat were too many to just dump. This saw the rise of the scripting languages likes of Groovy as well as the porting of other mainstream languages including Ruby (JRuby), Python (Jython) etc. However the true impact has come with the development of "entirely" new languages to target the JVM. The ones in focus right now are Scala and Clojure. These increased productivity in using these languages for programming on the JVM is unquestionable. However, we need to be mindful of the work that the "typical" programmer does, web development, which brings me back to the issue at hand, Web Development on the JVM today.

I have taken time to dabble with both Scala and Clojure and derived much joy in using either for building small glue applications, however i am now faced with the need to develop an enterprise level web application and i am looking to sticking with the JVM but not Java. In particular i am taking a closet look at using Clojure the tool chain right now including () are in a state of constant flux and require a lot of plumbing which the likes of Django (python) and Ruby on Rails (Ruby) do not require, perhaps due to their maturity. So it might be in my best interests to look at another possibility while keeping my eye on how Clojure and Scala evolve over the months/years

Monday, July 23, 2012 #

Five sixths of all software projects are not completed in the stipulated time and within budget, of these over one third get cancelled all together. What is surprising is how little documentation there is out there on how to NOT have your software project go wrong. The first step in doing this is by identifying the Root Causes as to why software projects fail. This, not surprisingly is one of three view points in appreciating software anti-pattterns Root Causes are mistakes in software devel

Monday, March 8, 2010 #

Alot of literature has and is being written about agile developement and its surrounding philosophies. In my quest to find the best way to express the importance of agile methodologies, i have found Robert C. Martin's "A Satire Of Two Companies" to be both the most concise and thorough! Enjoy the read!

Rufus Inc Project Kick Off
Your name is Bob. The date is January 3, 2001, and your head still aches from the recent millennial revelry. You are sitting in a conference room with several managers and a group of your peers. You are a project team leader. Your boss is there, and he has brought along all of his team leaders. His boss called the meeting. "We have a new project to develop," says your boss's boss. Call him BB. The points in his hair are so long that they scrape the ceiling. Your boss's points are just starting to grow, but he eagerly awaits the day when he can leave Brylcream stains on the acoustic tiles. BB describes the essence of the new market they have identified and the product they want to develop to exploit this market.
"We must have this new project up and working by fourth quarter October 1," BB demands.
"Nothing is of higher priority, so we are cancelling your current project."
The reaction in the room is stunned silence.
Months of work are simply going to be thrown away. Slowly, a murmur of objection begins to circulate around the conference table.
 
His points give off an evil green glow as BB meets the eyes of everyone in the room. One by one, that insidious stare reduces each attendee to quivering lumps of protoplasm. It is clear that he will brook no discussion on this matter.
Once silence has been restored, BB says, "We need to begin immediately. How long will it take you to do the analysis?"
You raise your hand. Your boss tries to stop you, but his spitwad misses you and you are unaware of his efforts.
 
"Sir, we can't tell you how long the analysis will take until we have some requirements."
"The requirements document won't be ready for 3 or 4 weeks," BB says, his points vibrating with frustration. "So, pretend that you have the requirements in front of you now. How long will you require for analysis?"
No one breathes. Everyone looks around to see whether anyone has some idea. "If analysis goes beyond April 1, we have a problem. Can you finish the analysis by then?"
Your boss visibly gathers his courage: "We'll find a way, sir!" His points grow 3 mm, and your headache increases by two Tylenol.
"Good." BB smiles. "Now, how long will it take to do the design?"
"Sir," you say. Your boss visibly pales. He is clearly worried that his 3 mms are at risk.
"Without an analysis, it will not be possible to tell you how long design will take."
BB's expression shifts beyond austere.
 
"PRETEND you have the analysis already!" he says, while fixing you with his vacant, beady little eyes. "How long will it take you to do the design?"
Two Tylenol are not going to cut it. Your boss, in a desperate attempt to save his new growth, babbles: "Well, sir, with only six months left to complete the project, design had better take no longer than 3 months."
 
"I'm glad you agree, Smithers!" BB says, beaming. Your boss relaxes. He knows his points are secure. After a while, he starts lightly humming the Brylcream jingle. BB continues, "So, analysis will be complete by April 1, design will be complete by July 1, and that gives you 3 months to implement the project. This meeting is an example of how well our new consensus and empowerment policies are working. Now, get out there and start working. I'll expect to see TQM plans and QIT assignments on my desk by next week. Oh, and don't forget that your crossfunctional team meetings and reports will be needed for next month's quality audit."
"Forget the Tylenol," you think to yourself as you return to your cubicle. "I need bourbon."
 
Visibly excited, your boss comes over to you and says, "Gosh, what a great meeting. I think we're really going to do some world shaking with this project." You nod in agreement, too disgusted to do anything else.
"Oh," your boss continues, "I almost forgot." He hands you a 30-page document. "Remember that the SEI is coming to do an evaluation next week. This is the evaluation guide. You need to read through it, memorize it, and then shred it.
It tells you how to answer any questions that the SEI auditors ask you. It also tells you what parts of the building you are allowed to take them to and what parts to avoid. We are determined to be a CMM level 3 organization by June!"
 
You and your peers start working on the analysis of the new project. This is difficult because you have no requirements. But from the 10-minute introduction given by BB on that fateful morning, you have some idea of what the product is supposed to do.
 
Corporate process demands that you begin by creating a use case document. You and your team begin enumerating use cases and drawing oval and stick diagrams.
Philosophical debates break out among the team members. There is disagreement as to whether certain use cases should be connected with <<extends>> or <<includes>> relationships.
Competing models are created, but nobody knows how to evaluate them. The debate continues, effectively paralyzing progress.
 
After a week, somebody finds the iceberg.com Web site, which recommends disposing entirely of <<extends>> and <<includes>> and replacing them with <<precedes>> and <<uses>>. The documents on this Web site, authored by Don Sengroiux, describes a method known as stalwart-analysis, which claims to be a step-by-step method for translating use cases into design diagrams.
More competing use case models are created using this new scheme, but again, people can't agree on how to evaluate them. The thrashing continues.
More and more, the use case meetings are driven by emotion rather than by reason. If it weren't for the fact that you don't have requirements, you'd be pretty upset by the lack of progress you are making.
The requirements document arrives on February 15. And then again on February 20, 25, and every week thereafter. Each new version contradicts the previous one. Clearly, the marketing folks who are writing the requirements, empowered though they might be, are not finding consensus.
 
At the same time, several new competing use case templates have been proposed by the various team members. Each template presents its own particularly creative way of delaying progress. The debates rage on.
On March 1, Prudence Putrigence, the process proctor, succeeds in integrating all the competing use case forms and templates into a single, all-encompassing form. Just the blank form is 15 pages long. She has managed to include every field that appeared on all the competing templates. She also presents a 159- page document describing how to fill out the use case form. All current use cases must be rewritten according to the new standard.
 
You marvel to yourself that it now requires 15 pages of fill-in-the-blank and essay questions to answer the question: What should the system do when the user presses Return? The corporate process (authored by L. E. Ott, famed author of "Holistic Analysis: A Progressive Dialectic for Software Engineers") insists that you discover all primary use cases, 87 percent of all secondary use cases, and 36.274 percent of all tertiary use cases before you can complete analysis and enter the design phase. You have no idea what a tertiary use case is. So in an attempt to meet this requirement, you try to get your use case document reviewed by the marketing department, which you hope will know what a tertiary use case is.
 
Unfortunately, the marketing folks are too busy with sales support to talk to you. Indeed, since the project started, you have not been able to get a single meeting with marketing, which has provided a never-ending stream of changing and contradictory requirements documents.
 
While one team has been spinning endlessly on the use case document, another team has been working out the domain model. Endless variations of UML documents are pouring out of this team. Every week, the model is reworked.
 
The team members can't decide whether to use <<interfaces>> or <<types>> in the model. A huge disagreement has been raging on the proper syntax and application of OCL. Others on the team just got back from a 5-day class on catabolism, and have been producing incredibly detailed and arcane diagrams that nobody else can fathom.
 
On March 27, with one week to go before analysis is to be complete, you have produced a sea of documents and diagrams but are no closer to a cogent analysis of the problem than you were on January 3.
****
And then, a miracle happens.
 
****
On Saturday, April 1, you check your e-mail from home. You see a memo from your boss to BB. It states unequivocally that you are done with the analysis!
You phone your boss and complain. "How could you have told BB that we were done with the analysis?"
"Have you looked at a calendar lately?" he responds. "It's April 1!"
The irony of that date does not escape you. "But we have so much more to think about. So much more to analyze! We haven't even decided whether to use <<extends>> or <<precedes>>!"
"Where is your evidence that you are not done?" inquires your boss, impatiently.
"Whaaa . . . ."
But he cuts you off. "Analysis can go on forever; it has to be stopped at some point. And since this is the date it was scheduled to stop, it has been stopped. Now, on Monday, I want you to gather up all existing analysis materials and put them into a public folder. Release that folder to Prudence so that she can log it in the CM system by Monday afternoon. Then get busy and start designing."
 
As you hang up the phone, you begin to consider the benefits of keeping a bottle of bourbon in your bottom desk drawer. They threw a party to celebrate the on-time completion of the analysis phase. BB gave a colon-stirring speech on empowerment. And your boss, another 3 mm taller, congratulated his team on the incredible show of unity and teamwork. Finally, the CIO takes the stage to tell everyone that the SEI audit went very well and to thank everyone for studying and shredding the evaluation guides that were passed out.
Level 3 now seems assured and will be awarded by June. (Scuttlebutt has it that managers at the level of BB and above are to receive significant bonuses once the SEI awards level 3.)
 
As the weeks flow by, you and your team work on the design of the system. Of course, you find that the analysis that the design is supposedly based on is flawedno, useless; no, worse than useless. But when you tell your boss that you need to go back and work some more on the analysis to shore up its weaker sections, he simply states, "The analysis phase is over. The only allowable activity is design. Now get back to
it."
 
So, you and your team hack the design as best you can, unsure of whether the requirements have been properly analyzed. Of course, it really doesn't matter much, since the requirements document is still thrashing with weekly revisions, and the marketing department still refuses to meet with you.
 
 
The design is a nightmare. Your boss recently misread a book named The Finish Line in which the author, Mark DeThomaso, blithely suggested that design documents should be taken down to code-level detail.
"If we are going to be working at that level of detail," you ask, "why don't we simply write the code instead?"
"Because then you wouldn't be designing, of course. And the only allowable activity in the design phase is design!"
"Besides," he continues, "we have just purchased a companywide license for Dandelion!
This tool enables 'Round the Horn Engineering!'
You are to transfer all design diagrams into this tool. It will automatically generate our code for us! It will also keep the design diagrams in sync with the code!"
Your boss hands you a brightly colored shrinkwrapped box containing the Dandelion distribution. You accept it numbly and shuffle off to your cubicle. Twelve hours, eight crashes, one disk reformatting, and eight shots of 151 later, you finally have the tool installed on your server.
You consider the week your team will lose while attending Dandelion training. Then you smile and think, "Any week I'm not here is a good week."
Design diagram after design diagram is created by your team. Dandelion makes it very difficult to draw these diagrams. There are dozens and dozens of deeply nested dialog boxes with funny text fields and check boxes that must all be filled in correctly. And then there's the problem of moving classes between packages.
At first, these diagram are driven from the use cases. But the requirements are changing so often that the use cases rapidly become meaningless.
Debates rage about whether VISITOR or DECORATOR design patterns should be used. One developer refuses to use VISITOR in any form, claiming that it's not a properly object-oriented construct. Someone refuses to use multiple inheritance, since it is the spawn of the devil.
Review meetings rapidly degenerate into debates about the meaning of object orientation, the definition of analysis versus design, or when to use aggregation versus association.
Midway through the design cycle, the marketing folks announce that they have rethought the focus of the system. Their new requirements document is completely restructured. They have eliminated several major feature areas and replaced them with feature areas that they anticipate customer surveys will show to be more appropriate.
You tell your boss that these changes mean that you need to reanalyze and redesign much of the system. But he says, "The analysis phase is system. But he says, "The analysis phase is over. The only allowable activity is design. Now
get back to it."
 
You suggest that it might be better to create a simple prototype to show to the marketing folks and even some potential customers. But your boss says, "The analysis phase is over. The only allowable activity is design. Now get back to it."
Hack, hack, hack, hack. You try to create some kind of a design document that might reflect the new requirements documents. However, the revolution of the requirements has not caused them to stop thrashing. Indeed, if anything, the wild oscillations of the requirements document have only increased in frequency and amplitude.
 
You slog your way through them.
 
On June 15, the Dandelion database gets corrupted. Apparently, the corruption has been progressive. Small errors in the DB accumulated over the months into bigger and bigger errors.
Eventually, the CASE tool just stopped working. Of course, the slowly encroaching corruption is present on all the backups.
Calls to the Dandelion technical support line go unanswered for several days. Finally, you receive a brief e-mail from Dandelion, informing you that this is a known problem and that the solution is to purchase the new version, which they promise will be ready some time next quarter, and then reenter all the diagrams by hand.
 
****
 
Then, on July 1 another miracle happens! You are done with the design!
 
Rather than go to your boss and complain, you stock your middle desk drawer with some vodka.
 
****
They threw a party to celebrate the on-time completion of the design phase and their graduation to CMM level 3. This time, you find BB's speech so stirring that you have to use the restroom before it begins.
New banners and plaques are all over your workplace. They show pictures of eagles and mountain climbers, and they talk about teamwork and empowerment. They read better after a few scotches. That reminds you that you need to clear out your file cabinet to make room for the brandy.
You and your team begin to code. But you rapidly discover that the design is lacking in some significant areas. Actually, it's lacking any significance at all. You convene a design session in one of the conference rooms to try to work through some of the nastier problems. But your boss catches you at it and disbands the meeting, saying, "The design phase is over. The only allowable activity is coding. Now get back to it."
 
****
 
The code generated by Dandelion is really hideous. It turns out that you and your team were using association and aggregation the wrong way, after all. All the generated code has to be edited to correct these flaws. Editing this code is extremely difficult because it has been instrumented with ugly comment blocks that have special syntax that Dandelion needs in order to keep the diagrams in sync with the code. If you accidentally alter one of these comments, the diagrams will be regenerated incorrectly. It turns out that "Round the Horn Engineering" requires an awful lot of effort.
The more you try to keep the code compatible with Dandelion, the more errors Dandelion generates. In the end, you give up and decide to keep the diagrams up to date manually. A second later, you decide that there's no point in keeping the diagrams up to date at all. Besides, who has time?
 
Your boss hires a consultant to build tools to count the number of lines of code that are being produced. He puts a big thermometer graph on the wall with the number 1,000,000 on the top.
Every day, he extends the red line to show how many lines have been added.
Three days after the thermometer appears on the wall, your boss stops you in the hall. "That graph isn't growing quickly enough. We need to have a million lines done by October 1."
"We aren't even sh-sh-sure that the proshect will require a m-million linezh," you blather.
"We have to have a million lines done by October 1," your boss reiterates. His points have grown again, and the Grecian formula he uses on them creates an aura of authority and competence.
"Are you sure your comment blocks are big enough?"
Then, in a flash of managerial insight, he says, "I have it! I want you to institute a new policy among the engineers. No line of code is to be longer than 20 characters. Any such line must be split into two or more preferably more. All existing code needs to be reworked to this standard. That'll get our line count up!"
 
You decide not to tell him that this will require two unscheduled work months. You decide not to tell him anything at all. You decide that intravenous injections of pure ethanol are the only solution. You make the appropriate arrangements.
Hack, hack, hack, and hack. You and your team madly code away. By August 1, your boss, frowning at the thermometer on the wall, institutes a mandatory 50-hour workweek.
 
Hack, hack, hack, and hack. By September 1st, the thermometer is at 1.2 million lines and your boss asks you to write a report describing why you exceeded the coding budget by 20 percent.
He institutes mandatory Saturdays and demands that the project be brought back down to a million lines. You start a campaign of remerging lines.
Hack, hack, hack, and hack. Tempers are flaring; people are quitting; QA is raining trouble reports down on you. Customers are demanding installation and user manuals; salespeople are demanding advance demonstrations for special customers; the requirements document is still thrashing, the marketing folks are complaining that the product isn't anything like they specified, and the liquor store won't accept your credit card anymore. Something has to give.
 
 On September 15, BB calls a meeting.
As he enters the room, his points are emitting clouds of steam. When he speaks, the bass overtones of his carefully manicured voice cause the pit of your stomach to roll over. "The QA manager has told me that this project has less than 50 percent of the required features implemented. He has also informed me that the system crashes all the time, yields wrong results, and is hideously slow. He has also complained that he cannot keep up with the continuous train of daily releases, each more buggy than the last!"
He stops for a few seconds, visibly trying to compose himself. "The QA manager estimates that, at this rate of development, we won't be able to ship the product until December!"
Actually, you think it's more like March, but you don't say anything. "December!" BB roars with such derision that people duck their heads as though he were pointing an assault rifle at them. "December is absolutely out of the question. Team leaders, I want new estimates on my desk in the morning.
I am hereby mandating 65-hour work weeks until this project is complete. And it better be complete by November 1."
 
As he leaves the conference room, he is heard to mutter: "Empowermentbah!"
* * *
Your boss is bald; his points are mounted on BB's wall. The fluorescent lights reflecting off his pate momentarily dazzle you.
"Do you have anything to drink?" he asks.
Having just finished your last bottle of Boone's Farm, you pull a bottle of Thunderbird from your bookshelf and pour it into his coffee mug.
"What's it going to take to get this project done? " he asks.
"We need to freeze the requirements, analyze them, design them, and then implement them," you say callously.
"By November 1?" your boss exclaims incredulously. "No way! Just get back to coding the damned thing." He storms out, scratching his vacant head.
 
A few days later, you find that your boss has been transferred to the corporate research division. Turnover has skyrocketed. Customers, informed at the last minute that their orders cannot be fulfilled on time, have begun to cancel their orders. Marketing is re-evaluating whether this product aligns with the overall goals of the company. Memos fly, heads roll, policies change, and things are, overall, pretty grim.
Finally, by March, after far too many sixty-five hour weeks, a very shaky version of the software is ready. In the field, bug-discovery rates are high, and the technical support staff are at their wits' end, trying to cope with the complaints and demands of the irate customers. Nobody is happy.
 
In April, BB decides to buy his way out of the problem by licensing a product produced by Rupert Industries and redistributing it. The customers are mollified, the marketing folks are smug, and you are laid off.
 
 
Rupert Industries: Project Alpha
 
Your name is Robert. The date is January 3, 2001. The quiet hours spent with your family this holiday have left you refreshed and ready for work. You are sitting in a conference room with your team of professionals. The manager of the division called the meeting.
"We have some ideas for a new project," says the division manager. Call him Russ. He is a high-strung British chap with more energy than a fusion reactor. He is ambitious and driven but understands the value of a team. Russ describes the essence of the new market opportunity the company has identified and introduces you to Jane, the marketing manager, who is responsible for defining the products that will address it.
Addressing you, Jane says, "We'd like to start defining our first product offering as soon as possible. When can you and your team meet with me?"
You reply, "We'll be done with the current iteration of our project this Friday. We can spare a few hours for you between now and then. After that, we'll take a few people from the team and dedicate them to you. We'll begin hiring their replacements and the new people for your team immediately."
"Great," says Russ, "but I want you to understand that it is critical that we have something to exhibit at the trade show coming up this July. If we can't be there with something significant, we'll lose the opportunity."
 
"I understand," you reply. "I don't yet know what it is that you have in mind, but I'm sure we can have something by July. I just can't tell you what that something will be right now. In any case, you and Jane are going to have complete control over what we developers do, so you can rest assured that by July, you'll have the most important things that can be accomplished in that time ready to exhibit."
 
Russ nods in satisfaction. He knows how this works. Your team has always kept him advised and allowed him to steer their development. He has the utmost confidence that your team will work on the most important things first and will produce a high-quality product.
 
* * *
 
"So, Robert," says Jane at their first meeting,
"How does your team feel about being split up?"
"We'll miss working with each other," you answer, "but some of us were getting pretty tired of that last project and are looking forward to a change. So, what are you people cooking up?"
Jane beams. "You know how much trouble our customers currently have . . ." And she spends a half hour or so describing the problem and possible solution.
"OK, wait a second" you respond. "I need to be clear about this." And so you and Jane talk about how this system might work. Some of her ideas aren't fully formed. You suggest possible solutions. She likes some of them. You continue discussing.
 
During the discussion, as each new topic is addressed, Jane writes user story cards. Each card represents something that the new system has to do. The cards accumulate on the table and are spread out in front of you. Both you and Jane point at them, pick them up, and make notes on them as you discuss the stories. The cards are powerful mnemonic devices that you can use to represent complex ideas that are barely formed.
 
At the end of the meeting, you say, "OK, I've got a general idea of what you want. I'm going to talk to the team about it. I imagine they'll want to run some experiments with various database structures and presentation formats. Next time we meet, it'll be as a group, and we'll start identifying the most important features of the system."
 
A week later, your nascent team meets with Jane. They spread the existing user story cards out on the table and begin to get into some of the details of the system.
The meeting is very dynamic. Jane presents the stories in the order of their importance. There is much discussion about each one. The developers are concerned about keeping the stories small enough to estimate and test. So they continually ask Jane to split one story into several smaller stories. Jane is concerned that each story have a clear business value and priority, so as she splits them, she makes sure that this stays true.
 
The stories accumulate on the table. Jane writes them, but the developers make notes on them as needed. Nobody tries to capture everything that is said; the cards are not meant to capture everything but are simply reminders of the conversation.
 
As the developers become more comfortable with the stories, they begin writing estimates on them. These estimates are crude and budgetary, but they give Jane an idea of what the story will cost.
 
At the end of the meeting, it is clear that many more stories could be discussed. It is also clear that the most important stories have been addressed and that they represent several months worth of work. Jane closes the meeting by taking the cards with her and promising to have a proposal for the first release in the morning.
 
* * *
 
The next morning, you reconvene the meeting. Jane chooses five cards and places them on the table.
"According to your estimates, these cards represent about one perfect team-week's worth of work. The last iteration of the previous project managed to get one perfect team-week done in 3 real weeks. If we can get these five stories done in 3 weeks, we'll be able to demonstrate them to Russ. That will make him feel very comfortable about our progress."
Jane is pushing it. The sheepish look on her face lets you know that she knows it too. You reply, "Jane, this is a new team, working on a new project. It's a bit presumptuous to expect that our velocity will be the same as the previous team's. However, I met with the team yesterday afternoon, and we all agreed that our initial velocity should, in fact, be set to one perfectweek for every 3 real-weeks. So you've lucked out on this one."
"Just remember," you continue, "that the story estimates and the story velocity are very tentative at this point. We'll learn more when we plan the iteration and even more when we implement it."
 
Jane looks over her glasses at you as if to say "Who's the boss around here, anyway?" and then smiles and says, "Yeah, don't worry. I know the drill by now."Jane then puts 15 more cards on the table. She says, "If we can get all these cards done by the end of March, we can turn the system over to our beta test customers. And we'll get good feedback from them."
 
You reply, "OK, so we've got our first iteration defined, and we have the stories for the next three iterations after that. These four iterations will make our first release."
 
"So," says Jane, can you really do these five stories in the next 3 weeks?"
"I don't know for sure, Jane," you reply. "Let's break them down into tasks and see what we get."
 
So Jane, you, and your team spend the next several hours taking each of the five stories that Jane chose for the first iteration and breaking them down into small tasks. The developers quickly realize that some of the tasks can be shared between stories and that other tasks have commonalities that can probably be taken advantage of. It is clear that potential designs are popping into the developers' heads. From time to time, they form little discussion knots and scribble UML diagrams on some cards.
 
Soon, the whiteboard is filled with the tasks that, once completed, will implement the five stories for this iteration. You start the sign-up process by saying, "OK, let's sign up for these tasks."
"I'll take the initial database generation." Says Pete. "That's what I did on the last project, and this doesn't look very different. I estimate it at two of my perfect workdays."
"OK, well, then, I'll take the login screen," says
Joe.
"Aw, darn," says Elaine, the junior member of the team, "I've never done a GUI, and kinda wanted to try that one."
 
"Ah, the impatience of youth," Joe says sagely, with a wink in your direction. "You can assist me with it, young Jedi." To Jane: "I think it'll take me about three of my perfect workdays."
 
One by one, the developers sign up for tasks and estimate them in terms of their own perfect workdays. Both you and Jane know that it is best to let the developers volunteer for tasks than to assign the tasks to them. You also know full well that you daren't challenge any of the developers' estimates. You know these people, and you trust them. You know that they are going to do the very best they can.
 
The developers know that they can't sign up for more perfect workdays than they finished in the last iteration they worked on. Once each developer has filled his or her schedule for the iteration, they stop signing up for tasks.
 
Eventually, all the developers have stopped signing up for tasks. But, of course, tasks are still left on the board.
 
"I was worried that that might happen," you say, "OK, there's only one thing to do, Jane. We've got too much to do in this iteration. What stories or tasks can we remove?"
Jane sighs. She knows that this is the only option. Working overtime at the beginning of a project is insane, and projects where she's tried it have not fared well.
 
So Jane starts to remove the least-important functionality. "Well, we really don't need the login screen just yet. We can simply start the system in the logged-in state."
"Rats!" cries Elaine. "I really wanted to do that."
"Patience, grasshopper." says Joe. "Those who wait for the bees to leave the hive will not have lips too swollen to relish the honey."
Elaine looks confused.
Everyone looks confused.
"So . . .," Jane continues, "I think we can also do away with . . ."
And so, bit by bit, the list of tasks shrinks. Developers who lose a task sign up for one of the remaining ones.
 
The negotiation is not painless. Several times, Jane exhibits obvious frustration and impatience.
Once, when tensions are especially high, Elaine volunteers, "I'll work extra hard to make up some of the missing time." You are about to correct her when, fortunately, Joe looks her in the eye and says, "When once you proceed down the dark path, forever will it dominate your destiny."
 
In the end, an iteration acceptable to Jane is reached. It's not what Jane wanted. Indeed, it is significantly less. But it's something the team feels that can be achieved in the next 3 weeks.
 
And, after all, it still addresses the most important things that Jane wanted in the iteration.
"So, Jane," you say when things had quieted down a bit, "when can we expect acceptance tests from you?"
Jane sighs. This is the other side of the coin. For every story the development team implements,
 
Jane must supply a suite of acceptance tests that prove that it works. And the team needs these long before the end of the iteration, since they will certainly point out differences in the way Jane and the developers imagine the system's behaviour.
 
"I'll get you some example test scripts today," Jane promises. "I'll add to them every day after that. You'll have the entire suite by the middle of the iteration."
 
* * *
 
The iteration begins on Monday morning with a flurry of Class, Responsibilities, Collaborators sessions. By midmorning, all the developers have assembled into pairs and are rapidly coding away.
"And now, my young apprentice," Joe says to Elaine, "you shall learn the mysteries of test-first design!"
 
"Wow, that sounds pretty rad," Elaine replies. "How do you do it?" Joe beams. It's clear that he has been anticipating this moment. "OK, what does the code do right now?"
"Huh?" replied Elaine, "It doesn't do anything at all; there is no code."
 
"So, consider our task; can you think of something the code should do?"
"Sure," Elaine said with youthful assurance,
"First, it should connect to the database." "And thereupon, what must needs be required to connecteth the database?"
"You sure talk weird," laughed Elaine. "I think we'd have to get the database object from some registry and call the Connect() method. "Ah, astute young wizard. Thou perceives correctly that we requireth an object within which we can cacheth the database object."
"Is 'cacheth' really a word?"
"It is when I say it! So, what test can we write that we know the database registry should pass?"
Elaine sighs. She knows she'll just have to play along. "We should be able to create a database object and pass it to the registry in a Store() method. And then we should be able to pull it out of the registry with a Get() method and make sure it's the same object."
"Oh, well said, my prepubescent sprite!" "Hay!"
"So, now, let's write a test function that proves your case."
"But shouldn't we write the database object and registry object first?"
"Ah, you've much to learn, my young impatient one. Just write the test first."
"But it won't even compile!"
"Are you sure? What if it did?"
"Uh . . ."
"Just write the test, Elaine. Trust me." And so Joe, Elaine, and all the other developers began to code their tasks, one test case at a time. The room in which they worked was abuzz with the conversations between the pairs. The murmur was punctuated by an occasional high five when a pair managed to finish a task or a difficult test case.
 
As development proceeded, the developers changed partners once or twice a day. Each developer got to see what all the others were doing, and so knowledge of the code spread generally throughout the team.
 
Whenever a pair finished something significant whether a whole task or simply an important part of a task they integrated what they had with the rest of the system. Thus, the code base grew daily, and integration difficulties were minimized.
 
The developers communicated with Jane on a daily basis. They'd go to her whenever they had a question about the functionality of the system or the interpretation of an acceptance test case.
 
Jane, good as her word, supplied the team with a steady stream of acceptance test scripts. The team read these carefully and thereby gained a much better understanding of what Jane expected the system to do.
By the beginning of the second week, there was enough functionality to demonstrate to Jane. She watched eagerly as the demonstration passed test case after test case.
"This is really cool," Jane said as the demonstration finally ended. "But this doesn't seem like one-third of the tasks. Is your velocity slower than anticipated?"
 
You grimace. You'd been waiting for a good time to mention this to Jane but now she was forcing the issue. "Yes, unfortunately, we are going more slowly than we had expected. The new application server we are using is turning out to be a pain to configure. Also, it takes forever to reboot, and we have to reboot it whenever we make even the slightest change to its configuration."
 
Jane eyes you with suspicion. The stress of last
Monday's negotiations had still not entirely dissipated. She says, "And what does this mean to our schedule? We can't slip it again, we just can't. Russ will have a fit! He'll haul us all into the woodshed and ream us some new ones."
 
You look Jane right in the eyes. There's no pleasant way to give someone news like this. So you just blurt out, "Look, if things keep going like they're going, we're not going to be done with everything by next Friday. Now it's possible that we'll figure out a way to go faster. But, frankly, I wouldn't depend on that. You should start thinking about one or two tasks that could be removed from the iteration without ruining the demonstration for Russ. Come hell or high water, we are going to give that demonstration on
Friday, and I don't think you want us to choose which tasks to omit."
 
"Aw forchrisakes!" Jane barely manages to stifle yelling that last word as she stalks away, shaking her head.
Not for the first time, you say to yourself, "Nobody ever promised me project management would be easy." You are pretty sure it won't be the last time, either.
 
Actually, things went a bit better than you had hoped. The team did, in fact, have to drop one task from the iteration, but Jane had chosen wisely, and the demonstration for Russ went without a hitch.
Russ was not impressed with the progress, but neither was he dismayed. He simply said, "This is pretty good. But remember, we have to be able to demonstrate this system at the trade show in July, and at this rate, it doesn't look like you'll have all that much to show." Jane, whose attitude had improved dramatically with the completion of the iteration, responded to Russ by saying, "Russ, this team is working hard, and well. When July comes around, I am confident that we'll have something significant to demonstrate. It won't be everything, and some of it may be smoke and mirrors, but we'll have something."
 
Painful though the last iteration was, it had calibrated your velocity numbers. The next iteration went much better. Not because your team got more done than in the last iteration but simply because the team didn't have to remove any tasks or stories in the middle of the iteration.
 
By the start of the fourth iteration, a natural rhythm has been established. Jane, you, and the team know exactly what to expect from one another. The team is running hard, but the pace is sustainable. You are confident that the team can keep up this pace for a year or more.
 
The number of surprises in the schedule diminishes to near zero; however, the number of surprises in the requirements does not. Jane and
Russ frequently look over the growing system and make recommendations or changes to the existing functionality. But all parties realize that these changes take time and must be scheduled.
So the changes do not cause anyone's expectations to be violated.
In March, there is a major demonstration of the system to the board of directors. The system is very limited and is not yet in a form good enough to take to the trade show, but progress is steady, and the board is reasonably impressed.
 
The second release goes even more smoothly than the first. By now, the team has figured out a way to automate Jane's acceptance test scripts. The team has also refactored the design of the system to the point that it is really easy to add new features and change old ones.
The second release was done by the end of June and was taken to the trade show. It had less in it than Jane and Russ would have liked, but it did demonstrate the most important features of the system. Although customers at the trade show noticed that certain features were missing, they were very impressed overall. You, Russ, and
Jane all returned from the trade show with smiles on your faces. You all felt as though this project was a winner.
 
Indeed, many months later, you are contacted by Rufus Inc. That company had been working on a system like this for its internal operations.
Rufus has canceled the development of that system after a death-march project and is negotiating to license your technology for its environment.
 
Indeed, things are looking up!

Tuesday, March 2, 2010 #

The .NET community, unlike the Java and python community do not provide Data Mining solutions outside the framework of their RDBMS MS SQL Server. In my quest to integrate Data mining into an existing ASP.NET enterprise solution running on MySQL, i was faced with quite the task!
In attempting to review existing solutions, i followed the following criteria:
  1. Open-source and free (not necessarily the same thing!)
  2. GUI for interactive data mining and exploration
  3. Concise, accessible and well documented API to use for embedded data mining
  4. Wide coverage of Data Mining algorithms
  5. Vibrant user community
Followign these, i zeroed down to WEKA and Orange
WEKA is a Java based collection of machine learning algorithms for solving data mining problems. It was initially developed in the Univesity of Waikato and is now maintaned by Pentaho.
Orange is a python based data visualization and analysis suite for data mining
Deciding to use WEKA, my first hurdle was interoperability. Alot has been done by both the .NET and Java communitie in ensuring fluid interop at different levels. After careful consideration, i decided to port the code entirely to .NET. Below is a quick highlight of my take on the different options.
Web Services: The obvious first choice, though i would have to babysit 2 servers on the same machine or otherwise, let alone the performance drawbacks.
Runtime Bridging (in-process) This would involve hosting both the JVM and the CLR in the same process. Tools for this purpose are mostly expensive (JNBridge, JIntegra, ..) and the open source solutions are C++ dependent and/or unsupported.
Porting  Code: Though initially scoffed at, i found it to be ideal for my purposes! I used  IKVM.
IKVM 
IKVM is an implementation of Java for Mono and .NET including a JVM, and the Java class libraries in .NET.
Steps
  • After downloading the weka source, i exported a single weka.jar file in Eclipse.
  • I downloaded the latest ikvm implementation and run the following command >ikvm.exe target:library weka.jar
  • This built a weka.dll .NET library
  • I referenced this a .NET project together with the JVM.DLL provided by ikvm and voila!
Sample source code to show a complete learning process. 
 
using System;
using System.IO;
using weka.classifiers;
using weka.classifiers.functions;
using weka.core;
using java.io;
using Attribute = weka.core.Attribute;
using System.Runtime.Serialization.Formatters.Binary;
using Console = System.Console;
using File = System.IO.File;
 
namespace TestApp
{
    internal class Sample
    {
        private void ExecuteWekaTutorial()
        {
            FastVector allAttributes = createAttributes();
            Instances learningDataset = CreateLearningDataSet(allAttributes);
            Classifier predictiveModel = LearnPredictiveModel(learningDataset);
            Evaluation evaluation = evaluatePredictiveModel(predictiveModel, learningDataset);
            Console.WriteLine(evaluation.toSummaryString());
            PredictUnknownCases(learningDataset, predictiveModel);
        }
 
        private FastVector createAttributes()
        {
            var ageAttribute = new Attribute("age");
            var genderAttributeValues = new FastVector(2);
            genderAttributeValues.addElement("male");
            genderAttributeValues.addElement("female");
            var genderAttribute = new Attribute("gender",
                                                genderAttributeValues);
            var numLoginsAttribute = new Attribute("numLogins");
            var allAttributes = new FastVector(3);
            allAttributes.addElement(ageAttribute);
            allAttributes.addElement(genderAttribute);
            allAttributes.addElement(numLoginsAttribute);
            return allAttributes;
        }
 
        private Instances CreateLearningDataSet(FastVector allAttributes)
        {
            var trainingDataSet = new Instances("wekaTutorial", allAttributes, 4);
            trainingDataSet.setClassIndex(2);
            AddInstance(trainingDataSet, 20.0, "male", 5);
            AddInstance(trainingDataSet, 30.0, "female", 2);
            AddInstance(trainingDataSet, 40.0, "male", 3);
            AddInstance(trainingDataSet, 35.0, "female", 4);
            return trainingDataSet;
        }
 
        private void AddInstance(Instances trainingDataSet,
                                 double age, String gender, int numLogins)
        {
            Instance instance = createInstance(trainingDataSet, age,
                                               gender, numLogins);
            trainingDataSet.add(instance);
        }
 
        private Instance createInstance(Instances associatedDataSet,
                                        double age, String gender, int numLogins)
        {
            var instance = new Instance(3);
            instance.setDataset(associatedDataSet);
            instance.setValue(0, age);
            instance.setValue(1, gender);
            instance.setValue(2, numLogins);
            return instance;
        }
 
        private Classifier LearnPredictiveModel(Instances learningDataset)
        {
            Classifier classifier = getClassifier();
            classifier.buildClassifier(learningDataset);
            return classifier;
        }
 
        private Classifier getClassifier()
        {
            var learner = new MyRBFNetwork();
            learner.setNumClusters(2);
 
            return learner;
        }
 
        private Evaluation evaluatePredictiveModel(Classifier classifier,
                                                   Instances learningDataset)
        {
            var learningSetEvaluation =
                new Evaluation(learningDataset);
            learningSetEvaluation.evaluateModel(classifier,
                                                learningDataset);
            return learningSetEvaluation;
        }
 
        private void PredictUnknownCases(Instances learningDataset,
                                         Classifier predictiveModel)
        {
            Instance testMaleInstance =
                createInstance(learningDataset, 45.0, "male", 0);
            Instance testFemaleInstance =
                createInstance(learningDataset, 45.0, "female", 0);
            double malePrediction =
                predictiveModel.classifyInstance(testMaleInstance);
            double femalePrediction =
                predictiveModel.classifyInstance(testFemaleInstance);
            Console.WriteLine("Predicted number of logins [age=45]: ");
            Console.WriteLine("\tMale = " + malePrediction);
            Console.WriteLine("\tFemale = " + femalePrediction);
        }
 
 
        private static void Main(string[] args)
        {
            var program = new Sample();
            program.ExecuteWekaTutorial();
        }
    }
}

IKVM is however not without fault, the GUI libraries are still below par but it should suffice for all the learning algorithms in embedded data mining. Part 2 will cover saving the models for future reference ( high performance!)


Monday, March 1, 2010 #

Who rules today?