Depending on the size of your organization, your operations, your budget, your business operations, and your green objectives, the process of devising your list of categories and subcategories, not to mention gathering the data to establish meaningful baselines, may be quite time-intensive. There are, after all, so many opportunities for greener IT-driven practices at any organization. If you're a law office, you might not need to worry at all about datacenter issues but may choose to focus on areas such as printing (paper and ink waste; energy-efficient printers; electronic document management) and travel reduction (videoconferencing). If you're a hardware manufacturer, you'd want to look at your supply chain, from the materials that go into your products (do they comply with ROHS?) to how they're packaged and distributed.
Planning for action
The next step is "identify gaps and next steps for green IT initiatives." See what's working and what potential each project has in its current state. Determine what projects should be launched to address particular green-tech goals. Moreover, determine which projects -- either those under way or being considered -- should be abandoned entirely: "For example, while cloud computing, data center outsourcing, and colocation services have a very powerful greening effect and represent a mature green datacenter strategy, company culture or regulations might prohibit CIOs from taking such actions."
Step three: "Document the goals of a green IT program to ultimately demonstrate value." Now that you've established your baseline, settled on the promised projects, and ditched the unpromising initiatives, it's time to figure out how to track each project's progress and tie it to specific green objectives so as to prove each project's worth. For example, you could measure how much energy your fleet of PCs consumes before implementing power management to set your baseline, then closely measure PC electricity usage once power management is in place. Over time, you could plot the savings on a colorful graph, both in dollars and in carbon emissions, and present it to shareholders to illustrate that the project is meeting stated green objectives of cutting energy waste and shrinking your company's carbon footprint.
The assessment process, according to the Forrester report, can also be an aid in "buttressing the case for more resources, skills, or budget." If, for example, you can demonstrate that your pilot server-virtualization project holds promise, you can make a compelling case for funding to train more of your IT staff on the art of virtualization.
Staying on track
Notably, Forrester does offer an IT maturity assessment service. I suspect you'll find a host of consulting companies offering similar services that may be worth exploring if the prospect of developing your baseline and devising green-tech targets is too daunting.