A project management framework as a set of process tools and templates used together to manage a project through its life cycle. A project management framework is how a project is managed to completion.
Each project should have a lifecycle that a minimum includes initiating, planning, executing, controlling, and closing phases as specified by the PMBOK Guide Fourth Edition. As you develop a project management framework for your organization and projects, you will want to break these large phases down into smaller, more concrete steps. In general, each step should have a tool, template, tips, techniques, and guidance that aid the project manager in carrying out that step.
An infinite number of project management frameworks are possible since the PMBOK Guide Fourth Edition is not prescriptive. They key is in providing the proper supports (tools, templates, etc.) for carrying out each step.