A milestone is a specific point within a project's life cycle which is used to measure the progress toward the ultimate goal. Milestones in project management are used as signal posts for a project's start or end date, external reviews or input, budget checks, submission of a major deliverable, etc.

The milestones are used to determine if the project should be continued, and if so, should there be any changes to the funding or requirements? There are many milestones that support the end-of-phase milestones or appear within certain life-cycle phases they are:

1) Scope Freeze Milestones: Scope freeze milestones are locations in the project’s timeline where the scope is frozen and further scope changes will not be allowed. In traditional project management, we often do not use scope freeze milestones because it is assumed that the scope is well-defined at project initiation. But on other projects, especially in IT, the project may begin based upon just an idea and the project’s scope must evolve as the project is being implemented. This is quite common with techniques such as Agile and Scrum.

Following approaches may be helpful in achieving scope baseline:-

• Work more with the customer until scope freeze is achieved.
• Agree to work in phases; proceed with partial project execution, clarify and agree to the rest of the scope during the course of the project. Pilot, prototype, or fit-to-business analysis mini-projects are helpful.
• Structure the project with many predetermined milestones and phases of short duration; such a project is far more likely to remain aligned with its ultimate objectives.

2) Design Freeze Milestones: A design freeze milestone is a point in a project where no further changes to the design of the product came be made without incurring a financial risk especially if the design must then go to manufacturing. The decision point for the freeze usually occurs at the end of a specific life-cycle phase.

There are several types of freezes, and they can occur in just about any type of project. However, they are most common in new product development (NPD) projects. In NPD projects, we normally have a both a specification freeze and a design freeze. The design freeze may be necessary for timely procurement of long lead items such as parts and tooling that are necessary for the final product to be manufactured. The timing of the design freeze is often dictated by the lead times and may be beyond the control of the company. Failing to meet design freeze points has a signifi cantly greater impact on manufacturing than engineering design.

Design freezes have the additional benefit of controlling downstream scope changes. However, even though design changes can be costly, they are often necessary for safety reasons, to protect the firm against possible product liability lawsuits, and to satisfy a customer’s specific needs.

3) Customer Approval Milestones: Project managers often neglect to include in the life-cycle phases timeline milestones and the accompanying time durations for customer approvals of the project’s schedule baseline with the mistaken belief that the approval process will happen quickly. The approval process in the project manager’s parent company may be known with some reasonable degree of certainly, but the same cannot be said for the client’s approval process. There are some factors that can impact the speed by which the approvals take place they are:-

• How many people are involved in the approval process
• Whether any of the people are new to the project
• When all of the necessary participants can find a mutually agreed upon time to meet
• The amount of time the people need to review the data, understand the data, and determine the impact of their decision
• Their knowledge of project management
• A review of the previous project decisions that were made by them or others
• How well they understand the impact of a delayed decision
• Whether they need additional information to make a decision.
• Whether the decision can be made verbally or if it must be written in report format.

Project managers must find out how long their customers need to make a decision, and it may be better to indicate customer approval as an activity rather than as a milestone.