In any organization, an important thing to consider is your rapport with the people around you. While every man is supposed to be for himself, an office is the perfect example of a group of people functioning together. Interdependency of departments, and individual people, make for a healthy working environment.
Interdependency helps in smooth functioning of the company as a whole. When every department is made aware that their work affects the functioning of the next department, efficiency of the entire organization improves, thus increasing output. Not just being professionally interdependent, even having a personal rapport with other employees of the firm works in the favour of everyone. Personally, work becomes a lot less taxing when there is someone to share the frustrations and brainstorm with. This in turn, again, increase output.