Sometimes sustainable computing is considered to be a buzzphrase for IT management. The argument goes like this; sustainability is a concept that deals with the social, environmental, and economic aspects of a given process. However, in fact what you have just described is what our IT management team does, we look at all these factors on a daily basis and make changes to the organization as needed. If we find new ideas, technologies, or processes that we determine are beneficial to the business, we 'in-corporate' them to our model. 'Sustainable Computing' is what we have been doing as long as our IT management team has been around.
Of course, this position is valid. In fact many of the easy sustainability changes can be pitched to management right along these lines e.g. getting IT to pay for the electricity they use, double-sided printing, recycling of used equipment, etc. These are items that save money and don't affect the quality of service enough not to implement.
But the necessary part is incorporating the sustainable principle into the metric that the department evaluates itself on. As this article from CIO explains, all too commonly the only metric used to evaluate performance is IT spending as a percent of revenue. The shortcomings of type of measurement are many; most salient is the fact that the budget for maintenance and the budget for R&D is collapsed into a single number. And this is where a sustainability guidelines can help out the most, by recognizing that maintenance needs to be minimized so that other programs such as research, innovation can be maximized to furthers the aims of the business. And I'm not just talking about fixed broken machines here, I'm talking about all maintenance - user problems, hardware issues, licensing schemes, environmental footprint, etc.
Want to measure your sustainable computing program? Measure your maintenance.