© 2010, Global Institute of
Flexible Systems Management
Model
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Global Journal of
Flexible Systems Management
2010, Vol. 11, No. 3, pp 21-38
Introduction
Today’s business is set in a global environment which
demands improved manufacturing and services. The
competition in the global market is forcing the companies
to develop strategies for manufacturing varieties of the parts
to meet the ever-growing and ever-changing demands of the
customer. Technological advancement and emerging markets
have opened up new ways of recognizing, adapting and
optimizing the flow of materials, information and resources.
To achieve these requirements manufacturing companies not
only need to be flexible
and responsive to the
changes, but also be able
to produce a variety of
products in a short span of time and with minimum cost.
The development in technology, material and customer
preferences has resulted in products with shorter life span.
New products and designs require changes in production
facilities. Moreover changing customer preferences and
intense competition have resulted in uncertainty in the
demand patterns. Recent breakthroughs in technology and
management technologies have made manufacturing sector
cope up with the changing environment. There is an ever
Effect of Scheduling and Manufacturing Flexibility
on the Performance of FMS
Syed Imran Shafiq
Mech. Engineering Section, University Polytechnic, Aligarh Muslim University, Aligarh, U.P. - 202002, India
Mohd. Faheem
Mech. Engineering Section, University Polytechnic, Aligarh Muslim University, Aligarh, U.P. - 202002, India
Mohammed Ali
Department of Mechanical Engineering, Aligarh Muslim University, Aligarh, U.P. - 202002, India
E-mail: mohdali234@rediffmail.com
Abstract
A framework for studying the effect of scheduling and manufacturing flexibility on the performance of flexible manufacturing
system has been presented in this paper. Scheduling and manufacturing flexibility are among the many manufacturing strategies
considered by the researchers to improve the system performance. In this paper in addition to scheduling and manufacturing
flexibility other manufacturing strategies being considered are system configuration, buffer capacity, routing flexibility
(manufacturing flexibility), number of pallets, volume of parts, dispatching and sequencing rules (scheduling). Performance of
systems is evaluated on make-span time, cost, machine utilization and queue waiting time. The key issues which are addressed
in this paper are the impact of different levels of routing flexibility, dispatching and sequencing rules and the increase in
number of pallets on the system performance. Simulation results indicate that, with increase in routing flexibility, make-span
time decreases. However the maximum benefit is obtained when routing flexibility increased from level 1 to 2. Combinations of
sequencing and dispatching rules are identified, which can yield best results for make-span, cost of production, queue waiting
time and machine utilization. It is suggested that the proposed methodology can be used in practice for not only setting
priorities on specific manufacturing factors but also for highlighting likely factor level combinations that could yield improved
shop performance.
Keywords: flexibility, make-span, manufacturing flexibility, scheduling, simulation
increasing pressure from suppliers, existing competitors, and
new competitors. The need of the hour for manufacturing
enterprise is to change from hard automation to flexible
automation. Flexible Manufacturing System (FMS) helps to
fulfil this requirement of the manufacturing enterprise.
Browne et al. (1984) has defined FMS as an integrated,
computer-controlled complex system of automated material
handling devices and numerically controlled tools that can
simultaneously process medium-size volumes of medium
variety parts. They have also proposed two basic
manufacturing flexibility types: machine flexibility and
routing flexibility. Based
on these basic flexibility
types other types of
flexibility like product
flexibility, process flexibility, operation flexibility, volume
flexibility, expansion flexibility and production flexibility
can be derived. Chen and Chung (1991) have proposed three
alternative sequencing models aimed a minimizing the
operation assignments and demonstrated the importance of
utilizing an alternate routing policy in FMS environment.
Caprihan and Wadhwa (1997) investigated the impact of
routing flexibility on an FMS with makespan as the
performance measure. They concluded that oversupply of
The developments in technology, material and customer
preferences have resulted in products with shorter life span.