According to PMBOK,
In the project management context, integration includes characteristics of unification, consolidation, articulation and integrative actions that are crucial to project completion, successfully managing stakeholder expectation, and meeting requirements. Project Integration Management entails making choices about resource allocation, making trade-offs among competing objectives and alternatives, and managing the interdependencies among the project management knowledge areas.
Integration is the job of the project manager because he is responsible for making sure the project stays on track. The PMBOK outlines six processes of Project Integration Management:
1. Develop the project charter – The project charter is a document that formally authorizes the project and gives the specific authority to the project manager to apply organizational resources to the project tasks or activities. The project charter should include a statement of work (SOW) or a first iteration or draft of what the project must deliver like deliverables. Detailed features are not included at this point. Those details are specified once the project team completes the analysis of the detailed user requirements and when they implement SDLC. Only enough detail is needed to plan the project activities in order to derive a project schedule and budget.
2. Develop the preliminary scope statement–Think of the preliminary scope statement as the first iteration or draft of what the project must deliver. This may include project deliverables such as project plan and the high level features and functionality of the application system. The preliminary scope statement can be provided by the project sponsor or by having the project team interview key project stakeholders.
3. Develop the project management plan - The project management plan is a document that details how the project will be executed, monitored, controlled, and closed. Although the project plan may evolve and change over the course of the project life cycle, it becomes the day-to-day tool that outlines how the project goal and objectives will be met. All subsidiary plans are integrated into this plan.
4. Direct and manage project execution – The project manager accomplishes the project management plan by integrating all of the project processes into one coordinated effort. Here the project work is carried out to complete the project’s scope.
5. Monitor and control project work – During the execution process, effort and resources will be expended to accomplish the project goal and objectives. Therefore, corrective actions may be necessary from time to time when the project’s performance strays from the project plan. On the other hand, preventive actions are sometimes necessary when the project team thinks or believes deviations from the project plan are likely. Corrective actions are reactive, while preventive actions are proactive. In addition, defect repair might be necessary when the project deliverables or processes do not meet quality standards.
6. Integrated change control – Change is inevitable during the project life cycle. Some approaches to project management and systems development embrace change, while other approaches may not embrace change well. Change control processes must be in place so that all proposed changes can be documented, reviewed, and decided upon. Then corrective, preventive, or defect repairs can be made effectively and efficiently. Changes affect project’s scope, schedule, budge and quality objectives. Thus changes should be incorporated into the project management plan.
7. Close the project– This includes both administrative and contract closure procedures to ensure that closure is brought to the project or project phase. Regardless of whether a project ends as planned or prematurely, a project should be closed out using the close project process.