There are different bases for industrial engineering initiatives.
Principles like principles of motion economy provide the basis for examining the present and proposed ways of work and design them so that they conform to the principles. Learning curve effect is one principle which posits that as cumulative production increases, the efficiency will increase. Whenever it is not happening, there is a need for focussed evaluation of the methods.
Organizations like National Institute of Occupational Safety and Health come out with various guidelines like maximum amount of weight that can be lifted manually, the peak pulse rate or heart rate and the recovery periods for heart rate etc. Design of human effort has to be done so that these guidelines are followed. Guidelines are available for computer workstations also.
Benchmarking among operators doing the same or similar jobs
Industrial engineers can observe the work of various operators and from these observations identify the efficient motions and validate those motions from occupational health and comfort considerations and then incorporate them into new effort designs.
Intuition of Industrial Engineers
As industrial engineers are undertaking various projects, some ideas come to them at periodic intervals regarding some of the activities that they have redesigned and are currently investigating.
Group based creativity
Every redesign has to include a question based group creativity sessions so that different persons think about different alternatives for accomplishing a task.
Model Based Approaches
OR models are appropriate example for model based approach.
Technique Based Approach
Value Engineering, SMED, Statistical Quality Control, Statistical Inventory Control, Six Sigma, Activity Based Management etc. are technique based approaches. If they have not been used so far on an operation or process they can be used and improvement can be realized.Original knol - http://knol.google.com/k/narayana-rao/bases-for-industrial-engineering/2utb2lsm2k7a/ 2293