Asource is the original material presented for the first time, and a source is a review or description of the original research.

A "primary" source is the original material presented for the first time, and a "secondary" source is a review or description of the original research.

Primary sources are unique materials on which other research is based. They are from the day and age included and have not been separated through elucidation or assessment.   They are generally the principal formal appearance of results in physical, print or electronic organization. They show unique reasoning, report a disclosure, or offer new data.  

Secondary sources are less effectively characterized than essential sources. Generally, they are accounts composed sometime later with the advantage of insight into the past. They are understandings and assessments of essential sources. Secondary sources are not confirm, yet rather discourse on and dialog of proof.

step 1: create a plan

step 2: inventory facility equipment/assets

step 3: create preventive maintenance procedures

step 4: create preventive maintenance schedules

step 5: train your maintenanceteam

step 6: analyze – adjust - improve

or

step 1 – pm procedure design: doing the effective things

step 2 – pm procedure scheduling: efficient use of people and resources

step 3 – pm lubrication engineering

step 4 – pm training: back on the chain gang

step 5 – pm program management plan

step 6 – communicate, communicate, communicate

what are your options to your question?