Better Software - June 2008 - (Page 24)

even though they’re not directly talking about it. For example, a lot of agilists like to talk about treating requirements like a prioritized stack that is created with initial requirements modeling at the beginning of the project. A recent survey [6] asked several questions pertaining to modeling in an effort to discover what is actually going on out there. The survey found that 77.7 percent of agile teams are doing initial requirements modeling and 77.2 percent do initial architecture modeling. It also found that 92.7 percent do whiteboard modeling, 65.9 percent do paper-based modeling (index cards, sticky notes, etc.), and 47 percent are using some sort of drawing tool or modeling tool. use the siMplest tools One of the practices of AM is to use the simplest tools. Figure 2 shows three modeling styles from the point of view of tool usage—any given project team will use one or more of these approaches throughout its lifecycle. A common theme is that regardless of your approach, you are likely at some point to use inclusive modeling tools such as whiteboards and paper to facilitate communication with both your stakeholders and with other team members. There will always be some sort of “skilled transformation” of the information identified by your inclusive modeling efforts to capture it in your tools, which are used to create working software. Furthermore, depending on tool availability and the skill sets of your team members, you might use more complex, software-based modeling tools. Agile MoDeling in prActice In this example, we chose to use the “Close to the Metal” strategy, as it best illustrates the advantages of a modeling tool without requiring as much customization as the “Agile MDA” strategy. We are developing an auction application for a company that will allow its employees, who are spread out around the world, to buy logo merchandise from its intranet as well as from the Internet. The project team is dispersed across several locations. The main team is in Toronto, including the team lead, three Web developers, and the product owner. Four developers with auction expertise are located in Bangalore, and business stakeholders are located throughout the world. We start our modeling with some initial requirements envisioning done in collaboration with the product owner and the business stakeholders. One of the most efficient approaches to describe requirements is to use a scenario-based approach with user stories, use cases, or usage scenarios. We’ll be creating use cases. From our working sessions we drew the following initial use case diagram of figure 3 (simplified for this article), where the “Place a Bid,” “Bill Buyer,” and “Ship Item” use cases have been identified as the most critical. This diagram and the underlying use cases will evolve throughout the project. Remember, the goal is to understand the scope at this point in the project; detailing the requirements will come out during the project iterations. While identifying the initial set of use cases, we also identified a starting set of non-functional, qualityof-service requirements, such as security (the application will be accessed from the Internet) and performance (the employees are all around the world). The architecture envisioning oc- Figure 1: The lifecycle of agile model-driven development Figure 2: Three tool strategies for AMDD 24 BETTER SOFTWARE JUNE 2008 www.StickyMinds.com http://www.StickyMinds.com

Table of Contents Feed for the Digital Edition of Better Software - June 2008

Better Software - June 2008 Contents Mark Your Calendar Contributors Technically Speaking eLightenment Code Craft Test Connection Management Chronicles Agile Model-Driven Development The Myth of Risk Management Stop the Insanity! Product Announcements 10 Things You Might Not Know About … The Last Word Ad Index

Better Software - June 2008

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