I've been doing some research recently around organisational change and innovation (can you tell?) and as part of that came across this simple model (from Knoster, Villa and Thousand) detailing in straightforward terms five key elements that are required to achieve change: vision, skills, incentives, resources, and an action plan. The vision, central to the direction and goal-setting, requires skills to realise, incentives to aid adoption, momentum and motivation, and adequate resources to fulfil it. The action plan runs as a consistent guiding foundation throughout the process of change.
And something I particularly liked - the model also rather neatly reveals what happens if one of these key elements is missing. Smart.
(I couldn't find the original on the web to link to but the source of this model is: Knoster T, Villa R, & Thousand J. (2000). A Framework for Thinking about Systems Change. In R. Villa & J. Thousand)