Petition Vote by Govenment Departement as opposed to One Party runs everything

To discuss the benefits of the voting system been split by departement. At the moment we have evolved through natural selection to a clan based system, where one party wins an election and one man elects a cabinet.
In any business, where survival of the organisation (the country) is the driving force for selection, rather than the survival of the individual, each depertement retains its 'Minister' as long as they perform. At no point is a successful head of departement removed because of failings in other departements.
The Misistry responsible for decising what departement receives what finance would in itself be votable for, and would in effect be the most important depertement when voting.
Such a system would allow us to vote in the best engineers to run the Energy policy (assuming they would be willing to set up a suitable Party), and keep them in place if they do a good job.
The whole of Goventment could then evolve to serve the people, rather than the party and lobyists.