Most requirement specifications use the word shall to denote something that is required, while reserving the will for simple statement about the future (especially since "going to" is typically seen as too informal for legal contexts).

Where we use shall and will?

As a general rule, use 'will' for affirmative and negative sentences about the future. Use 'will' for requests too. If you want to make an offer or suggestion with I/we, use 'shall' in the question form. For very formal statements, especially to describe obligations, use 'shall'.

What is the shall of specification?

Most requirement specifications use the word shall to denote a requirement. The word will is reserved for a statement of fact. ... Well-written requirement specifications define these words near the beginning of the document.