Abstract
The Manufacturing Integration Model (MIM) provides a method for analyzing the lost productivity due to low inventories. Many popular Just-In-Time techniques lead one to believe that inventories can be reduced without an affect upon production rates, however this has not proven the case in many applications. Little's Law, which states that production is equal to inventory divided by flow time, establishes the positive relationship between inventory and production. Using this law, when inventories drop, production will also drop unless flow time decreases an equal percentage to the reduction in inventory. MIM provides a means to study the relationship between inventory and flow time. In this sense, MIM is the integration of Little's Law for all combinations of inventory and flow time. MIM defines the relationship between inventory and flow time as being a function of capacity, flexibility, balance and work in-process levels. But flexibility can not be quantified mathematically so computer simulation is used to solve this integration equation. Computer simulation is used to identify the net production rate from a combination of flexibility, balance and work in-process levels. Then, increases in flexibility can be described and their relative effects can be quantified using simulation to solve the integration equation. MIM provides a mathematical model for analyzing manufacturing productivity. But instead of using approximate solutions, it defines a specific role for computer simulation to solve the complicated integration equation.