This is one of the key components of a Just-in-Time production system (Lean). In order to achieve a balanced work flow, cycle time equal to Takt time, and high quality, work must be standardized at all operations for optimum efficiency and consistency.
Standardized work is not equivalent to the typical American concept of production standards or efficiency standards within a standard cost system. It refers to the systematic determination and documentation of work element sequence and process for each operation. The objective is to clearly communicate to the operator exactly how the job should be performed. Variability - and the inefficiency that goes with it - is removed through scientific analysis of the operation, and by eliminating: "adjustment", searching for tools and parts, excess movements, double-handling, and awkward ergonomics.
MoreSteam Toolbox: Standardized Work - http://www.moresteam.com/lean/standardized-work.cfm