Geocentric model the coordinate system in order to predict the motions of planetary bodies, though doing so may make calculations easier to perform or interpret. A geocentric coordinate system can be more convenient when dealing only with bodies mostly influenced by the gravity of the Earth (such as artificial satellites and the Moon), or when calculating what the sky will look like when viewed from Earth (as opposed to an imaginary observer looking down on the entire solar system, where a different coordinate system might be more convenient). The Ptolemaic model of the solar system held sway into the early modern age;
Procedure (term) Procedure (term) A procedure is a document written to support a "policy directive". A procedure is designed to describe who, what, where, when, and why by means of establishing corporate accountability in support of the implementation of a "policy". The "how" is further documented by each organizational unit in the form of "work instructions" which aims to further support a procedure by providing greater detail. As an example, suppose a manufacturing facility established a policy that all overtime shall be approved. A procedure can be created to establish “Who” can approve overtime (ranks, roles & responsibilities), "What" forms or systems