Just as the best musicians in the world cannot perform a great sounding symphony without a conductor, the best collection of best engineers cannot successfully complete a project without a project manager. The project manager can be a person or a group, as is very often the case with open source software.

Project
A project is "a temporary endeavor undertaken to create a unique product, service, or result" (PMBOK Guide, 4th edition). A project is temporary in the sense that the project itself will not endure forever. The results of a project might endure for centuries (e.g. construction of the pyramids), but the project itself has a discrete start and end. The project could reach its end for one or more of the following reasons:

1. The objectives of the project have been achieved
2. The project is no longer feasible
3. The project is no longer required

Every project is unique in the sense that it creates a new result (product or service). Even though every project is unique, different kinds of projects have similar needs and requirements. For example, almost every software development project uses some kind of bug tracking process and software. New projects can benefit from knowledge of processes, skills, tools and techniques implemented in successfully completed projects. Nevertheless, due to the uniqueness of a project, uncertainties always remain about the expected outcomes of the project.

• projects have specific objectives
• projects are temporary endeavors so they must have a definite start and end
• Projects are developed with progressive elaboration i.e. the project is defined broadly and specific details are added as the project progresses through phases
• changes are expected and processes need to put in place to manage change
• project managers manage the project and ensure that the team is working to meet the project objectives
• budget compliance, product features, product quality, time, and customer satisfaction are success measures of a project
• projects are unique and thus involve uncertainty
• project exist within an organization and requiring input from the organization and returning capabilities back to the organization. project cannot operate and closed systems.

Operations
Operations are "permanent endeavors that produce repetitive outputs". Building a care on an assembly line is not a project. It is an operation. Workers perform the same tasks day after day.

Project Management
Project management is the "application of knowledge, skills, tools, and techniques to project activities to meet the project requirements" (PMBOK Guide, 4th edition). Projects are managed by project managers. The ensure that the team is working to meet the project objectives and proper resources are being allocated to the project.

Every project is constrained by its scope, cost, and time.
- Scope: what should be accomplished in the project?
- Cost: how much will it cost to complete the project?
- Time: how long will it take to complete the project?
Managing a project involves making trade-offs between scope, cost and time.

Project management provides many advantages, the most important ones are listed below:

• Efficient management of resources (human, capital, physical)
• Shorter and more realistic development times
• Better coordination between everyone involved in the project

Stakeholders
Stakeholders are people who are involved in a project's activities or could be affected by the project's activities e.g. customers, staff, project team, project sponsor, and project opponents. The needs and expectations of stakeholders are important during project conception and throughout the life of the project. Successful project manager maintain good relations with stakeholders and work towards fulfilling the needs of stakeholders while managing their expectations.