The Scrum Master is a servant leader
A Project Manager is supposed to bring a project to a successful conclusion. A Scrum Master is supposed to empower the Scrum Team.
The Scrum Master is a servant-leader for the Scrum Team. The Scrum Master exists to serve the team, puts the needs of the team first. This with the firm belief that you get the best out of people when you empower them.
A Project Manager is responsible to meet the project objective. Within Scrum there is no such role for a Scrum Master. The role that comes closest is the Product Owner, who should maximize value from the product.
But there’s a sweet difference between meeting project objectives and maximizing product value!
The Scrum Master should help the Product Owner with backlog management and product planning, as an expert of the tools and techniques. The Scrum Master should also make sure that the goals, scope and product domain are clear. This all with the aim that they can do their job the best possible way.
The Product Owner and the Development Team plan the work in a sprint. The Development Team self-organizes their work and no-one tells them how they should build the product increment. The Scrum Master is there to ensure they can do the work the best way possible, making sure that impediments are removed quickly.
So: A project Manager’s reason of being is to plan, execute and deliver a project according to requirements, within budget and in time.
A Scrum Master’s reason of being is to make sure that Product Owner and Scrum Team are enabled to maximize the value of the product. As said: a whole different beast.
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