A long time ago, someone came up with ADDIE for ISD. I'd like to recommend ADDIE for OD.
Let me translate that into English for you.
ISD stands for Instructional Systems Design which is the field of practice where experts in industrial training create sound, performance-based courses for topics such as safety, quality, and power plant operations. ISD is pretty hardcore.
I first encountered ISD when I entered the field of Training and Development (aka T&D) as a training specialist at nuclear power plants over thirty years ago.
A process framework that Instructional Designers were using at that time, was known as ADDIE. It's an acronym for a 5-phase systematic process approach to training.
ADDIE stands for Analysis, Design, Development, Implementation, and Evaluation. Pretty cool, if you ask me. [I know. This officially makes me a nerd. But as a confirmed INTP, I like things such as ADDIE quite a bit.]
(For more on ADDIE, see this page on Don Clark's website.)
Some years later, it occurred to me that ADDIE is good for more than just training programs. In a brainstorm flash, it came to me that ADDIE describes the work of a consultant, including Organization Development (OD).
The other day, a connection on LinkedIn commented that she encountered ADDIE as a change management tool in a course on Organizational Change.
Yes! I replied. That makes sense to me.
As a student of  David (Designing Organizations for High Performance) Hanna, I have long thought that ADDIE could capture quite well the steps in an OD process:
Assess the current organization - Organization development starts with assessment. With asking questions. With gathering data. With forming a team. Methods such as SWOT can be used at this stage.
The output of this stage is a complete assessment of the current organization, including its strengths and its improvement needs.
Design  the improved organization - The design step is the visionary step, where the desired organization is envisioned, described and captured somehow in words (and pictures perhaps). The OD method of Appreciative Inquiry (aka AI) can play a part here as the team dreams about the desired state. 
The output of this stage is a set of goals for the transformation of the organization.
Develop the action plan for bringing about the improvement - Next the vision and goals are translated into the action steps that will be carried out. Work is assigned. The schedule is laid out, along with the resources needed. All this so that the journey can begin from where we are now to where we want to be.
Implement the action plan - The work begins. The first steps are taken. Progress checks are held. Updates are provided. Coaches assess and intervene to assist and support individuals and teams toward success. Accomplishments are recognized and celebrated.
Evaluate the outcomes - When key milestones are reached, evaluation kicks in to determine How the organization is doing vis a vis the goals of the transformation. 
Throughout the five phases of ADDIE for OD, a core transformation team provides the steering, the spark of faith, and the continuity needed to see it through.
The OD consultant, much like a humble sherpa, guides, inspires, counsels, and on occasion provides the kick in the pants that the organization may need during the change journey.
Addendum:  For those wondering about Organization Development...An organization is the people. Take the people away and what do you have? Nada. So OD is about people.
The people who work within an organization have roles to play and relationships to manage. They have internal and external customers to satisfy. They have work to do, expectations to meet, and results to deliver.  All of which is happening in the midst of ever-changing conditions.
What OD does is help the people to change. Change, as Charles Handy once wisely said, is another word for learning. So OD is about learning and change.

In organizations, people are working in coordination with other people. So the team is the basic unit of focus. OD therefore is about teams and team building.
Stepping back, an organization has numerous teams. These various teams are part of the process (what we do here) and culture (how we do it) of the organization, doing their functional part (e.g. sales, IT, finance, HR, operations etc), interacting with other teams, hopefully well coordinated and aligned around the goals of the organization. This bigger picture we call "the system."
And that is also what OD is about.
Terrence Seamon has been enjoying a long run in the fields of Training and Organization Development. Follow him on twitter @tseamon.