What is the Mythical Man Month?
It is a concept that attempts to explain how throwing more bodies at a problem where the work is creative and non-partitionable will not result in the increased productivity that can be realized in partitionable work such as factory work.
How does it apply to software development?
Software development is still rather immature in nature. It is less structured compared to other sciences. It has a higher degree of creativity involved. It has highly customized knowledge specific to both the vertical of the institution and how the institution itself operates.
How is it different than other areas of IT such as system administration
System Administration has a higher degree of organization and specificity of scope than Software Development. The expectation is often that System Administration is broken down into several categorizations of specialization while in Software Development, often times the expectation is of a generalist who has intermediate to expert knowledge in all topics, for example, “Full Stack Developer”
What can be done to alleviate it?
Set expectations early as to what a person or group is capable of delivering early on. Hold the line on scope creep. Keep stakeholders informed of progress, challenges and opportunities. When being asked to stretch more, be polite but firm as to how that stretch creates risk of the overall project and provide options proactively of how that can be addressed.