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A Computer Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next Page M S BE aG F 60 RESEARCH FEATURE Figure 2. A GQM + Strategies model for ABC, a company that provides its customers with information services through the Web. GQM + Strategies enforces the explicit documentation of the relevant context factors and assumptions that are necessary for understanding and evaluating each goal. A Goal + Strategies element consists of a goal and an associated strategy (bottom of each goal box). Each element, in turn, is associated with a GQM graph (green rectangle to the right of the goal) representing questions and metrics as well as an interpretation model that evaluates if the goal was achieved. goals for various parts of the organization, such as software, hardware, and marketing. An organization might devise a separate set of strategies to deal with these lowerlevel goals. The number of goal and strategy levels depends on the organization’s internal structure. Assumptions and context information about the organization strongly influence the definition of goals and strategies. Measuring the effectiveness and the accomplishment of goals and the effectiveness of strategies at all levels is critical for business success. And making goals connected and transparent at all levels helps in communicating and achieving them. What most organizations need is support for these concepts. The components in Figure 1 provide this support by allowing multiple goal levels and multiple strategies for each goal (a GQM + Strategies element), as well as a measurement plan (GQM graph). The GQM + Strategies element provides the basic components for deriving the goals and strategies as influenced by the context; the basic known facts about the market, the organization, the product, and so on; and the assumptions—factors that are assumed or guessed but not known for sure. A key element is making the context and assumptions explicit so that they can be verified. The relevant context and assumptions aid in defining the rationale for choosing specific goals and strategies. A set COMPUTER Business level Software level Project level GQM + Strategies elements Goal 1: Increase profit from software service usage Strategy 1: Deliver added functionality Goal 2: Deliver 5% new functionality every 6 months within 10% of budget Strategy 2: Use MoSCoW and Cocomo Goal 3: Apply MoSCoW and Cocomo effectively Strategy 3: Conduct training, determine tools, perform pilot study GQM goals G1: Evaluate trend in profit G2: Evaluate functional growth of each release G3: Evaluate effectiveness of MoSCow and Cocomo Questions Metrics Interpretation model Q1: What is the current profit? Q2: What is the profit for year 2 and year 3? Q3: How many M requirements in each release? Q4: How long between releases? Q5: Cost estimation accuracy? BV: budget variance Q6: How extensive was the training? Q7: What is cost of training? P0: current annual profit PX: annual profit for year x MR: number of customerrequested requirements (M) implemented RD: release duration NT: number of trainees TC: hours spent in training If P2 0 and P3 2 and … then goal is satisfied of predefined goals and strategies can become part of an organization-specific experience base and allow different parts of the organization to select and adapt predefined goals and strategies. Associated with each GQM + Strategies element is a measurement plan that uses the GQM approach measurement and evaluation framework to specify how to evaluate the goal, what data to collect, and how to interpret that data. The nodes of each GQM graph consist of a measurement goal, which describes what knowledge needs to be gained from the measurement activity; a set of questions to be answered; the metrics and data items required to answer the questions; and an interpretation model that specifies how the data items are to be combined and what the criteria are for determining the goal’s success. The nodes are related semihierarchically. A goal can have several associated measurement goals, each of which is the basis for an entire GQM graph. However, different GQM structures are likely to use some of the same questions and metrics, and interpretation models might combine data from different GQM structures, thus optimizing metrics collection. The results of the lower-level interpretation models feed into the higher-level ones to provide feedback on lower-level goal achievement. A Computer Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next Page M S BE aG F … …
A Computer Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next Page M S BE aG F With the complete model, an organization can not only define measurement consistent with larger, upper-level organizational concerns, but also interpret and roll up the resulting measurement data at each level. AN APPLICATION To illustrate the features of our approach, we consider a fictitious but representative type of organization, ABC, which provides information services to its customers through the Web. Customers do not buy the software, but rather pay a service fee for access to information and to software that searches, analyzes, and presents that information. Thus, the business model implies that the number of customer accesses to ABC’s system determines the company’s revenue. Figure 2 represents a model of this application. Business goals Although the approach is flexible enough to accommodate several different entry points, the starting point of the GQM + Strategies process in this example is a business goal. As Goal 1 shows, one of ABC’s business goals is to increase profit from software service use. The GQM + Strategies approach enforces the explicit documentation of the relevant context factors and assumptions necessary for understanding and evaluating each goal. For Goal 1, one such context factor is that how often customers access ABC software products determines the amount of revenue generated at ABC. The GQM + Strategies goal template documents other details. Each template includes the desired magnitude of improvement, the time frame for achieving the goal, the scope of responsibility for achieving the goal, and any constraints or conflicting goals as well as relationships to other goals. Figure 3 shows a partial template for Goal 1. The GQM graph in Figure 2 is based on the measurement goal, G1. In full GQM notation, G1 is Analyze the trend in profit for the purpose of evaluation with respect to a 10 percent increase in annual income per year from the point of view of ABC’s management in the context of the ABC organization. This goal leads to questions Q1 and Q2: What is the current profit (measured by P 0 ), and what is the profit for each succeeding year (as measured by P x )? The decision maker analyzes the results using the criteria incorporated in the interpretation model (far right), which says that Starting in year 2, if the profit for the current year (P ) is 2 at least 10 percent (1.1 times) higher than the profit for the initial preceding year (P ), then the goal has been satisfied. 1 Activity: Increase Focus: Net income Object: ABC Web services Magnitude: 10% per year Time frame: Annually, beginning in 2 years Scope: Development groups assessed at CMMI level 2 or higher Constraints: Available resources, ability to sustain CMMI levels Relations: CMMI-related goals Figure 3. Business goal “Increase pro t from software service usage” expressed in the GQM + Strategies goal template. Business goals are at the top level of the GQM + Strategies model. They become measurable through the derivation of one or more GQM graphs, which are then associated with other GQM graphs at other organizational levels. The full interpretation model, not shown for simplicity, includes an “else” part related to the effectiveness of the chosen strategies. The strategies associated with each goal come from a list of potential strategies that the GQM + Strategies user has enumerated, taking into account influencing context factors. Possible strategies for meeting Goal 1 are to deliver added capabilities to encourage heavier system use, increase rates charged to customers, or reduce development costs. The user opted for the strategy of delivering added functionality in the product releases at regular and frequent intervals. At this point, the user must also make explicit the assumption that this added functionality will lead to increased customer satisfaction, which will in turn lead to heavier use. The assumption is that ABC has enough projects with a Capability Maturity Model Integration maturity level greater than 1 that, if just those projects provide a 15 percent improvement, ABC will see a 10 percent improvement overall. In general, all context information and assumptions are attached to goals, strategies, and their relations (as Figure 1 shows) and are documented in a corresponding graph (not shown). Software-development goals At the next level down in the model is a goal derived from the strategy (or strategies) chosen at the top level. Goal 2 is to deliver a new release of the software every six months that incorporates at least 5 percent more functionality than the previous release and to keep the cost of this increased functionality to within 10 percent of the current budget. These are really two interrelated but separate software goals, so the user defines them in separate GQM + Strategies goal templates. Figure 4 elaborates the first of these goals (increasing functionality by 5 percent). At this level, the goal is specific to software development, so it is treated as APRIL 2010 A Computer Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next Page M S BE aG F 61
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