Worship order. It's something most of us use every week to inform our planning and help us prepare for Sunday. (Chances are, you have one sitting on your desk right now.) It's an ancient practice - a structure we use to organize and plan worship, based on a certain order of sacred elements - readings, music, sermon, offering, sometimes Communion.
For most of us, there is structure and order to our worship, one that is informed by tradition, ritual, and practice. For some, the worship order is more flexible, embedding contemporary elements and expressions of faith into the traditional liturgy, connecting various ministries to the life of the church. For others, worship is seen as a time-honored tradition, something historical, preserving the patterns and practices from the Early Church.
No matter what your particular worship order looks like, I bet we'd find a few things in common if we compared them. Because the underlying structure - the rhythm of the liturgy - has stood the test of time (we're talking almost 2,000 years here).
Like I said, it's an ancient practice.