Journal Minimizing Flowtime

Scheduling in static jobshops for minimizing mean flowtime subject to minimum total deviation of job completion times
by
Viswanath Kumar Ganesan and Appa Iyer Sivakumar
Problem
The journal from Viswanath Kumar Ganesan and Appa Iyer Sivakumar discussed about   scheduling in static jobshops for minimizing mean flow time.   When jobs have to be delivered for a customized assembly or delivery, early completion of jobs is actually undesirable in delivery condition.   Particularly, when the finished jobs causes holding cost till other machining job orders complete.  

Problem Statement
How minimizing mean flow time can minimize raw material, finished good inventory, and total deviation of job completion time?

Theory
Total absolute differences in completion (TADC) is used as an alternative measurement.   Minimizing TADC in a jobshops environment helps in achieveing closeness of jobs’ completion but doesn not minimize mean flowtime of job.   Pinedo and Chao assumed that minimization of mean flowtime is equivalent to minimizing the work-in-process inventory or the average throughout time spent by a job in the shop.   The difference between minimizing variation of completion times and minimizing mean flowtime is at the type of performance measurement.   Minimizing flowtime is a regular measure of performance whereas minimizing variation of completion times is a non-regular measure of a performance.   In minimizing flowtime the job completion times is not decreasing.   So, it is called regular.

Research
Integrated procuring, production, until delivery system is important due to the large various types of products.   Manufacturing system is suggested to consider right points and right time in part of delivery.   The products should be delivered punctually.   Since the closeness of the job completions is the goal of the firm, they prefer to adapt schedule with minimum length for each job.   So, there will be an opportunity to minimize raw material or finished good...