Development involves organizing and planning all the variables that go into a project, including deciding materials, creating a budget and creating tasks for team members. It also involves the processes needed to complete a project, like changing the plans throughout project completion and identifying areas of improvement to help the project run more smoothly.
Project execution is the phase in a project’s life cycle where everything in the project plan is put into action and the actual work is performed. It is the result of and comes after project scheduling and project planning, and is where most of the time and effort of your project take place. That means that the way your execute project management is critically important.
The testing phase is to evaluate and test declared requirements, features, and expectations regarding the project prior to its delivery in order to ensure the project matches initial requirements stated in specification documents