Seeking best practice and process to follow- for retiring and obsoleting PeopleSoft objects

seeking out the best practice and steps to retire/decommison customizations that applied to the PS delivered vanilla code.
the type of objects can be many: page, component, menu, sql, a/e, peoplecode, a/e, sqr, cobol etc,

our I/S department is in a need to establish a standard procedure  to follow-through so when a business decision is made to retire and uncustomize a PeopleSoft object, the result can be clean and effective,

Please share with us your approach and practice, thank you!