I explain that role of Industrial engineering by stating that all systems are designed by functional systems specialists first and then they are evaluated and improved by industrial engineers. Industrial engineering is a specialized engineering activity. Safety engineering, reliability engineering etc. are some more specialized engineering branches that have a role in systems design.
In management systems also the original design is done by that functional management specialist and industrial engineers improve efficiency in the next iteration of design.
Quan-qing Li and Ming Li of Zhengzhou Institute of Aeronautical Industry Management expressed the same view in their paper "Thinking about the Application and Development Strategy of Industrial Engineering" presented in the IEEE 2011 conference on Industrial Engineering.
Every system has inputs, conversion process and output. The system design involves both specialized engineering technology and industrial engineering technology. The specialized engineering technology solves the problem of "is it possible?" It makes the system come into existence and deliver the required output. It is industrial engineering technology that will make the system give good output from the given resources. It makes the system run with high efficiency and low cost. "Improving elements of operations" and "Seeking optimization" are the characteristic of Industrial engineering.
Many times entrepreneurs neglect industrial engineering because even without IE, the system is running and giving desired output. The short-sighted entrepreneurs do not see the waste that is being incurred in the system. Many times it is invisible to them until they lose the battle in the market place due to high cost of their product.