Flexibility Analysis

Manufacturing process reengineering for mass customization by using flexibility analysis

Flexibility is an important design objective, since it
represents the ability of a design to accommodate
process variations, such as product demand, feedstream
quality and physical properties. The major
concern in incorporating flexibility in the design of
process systems is how to determine a measure of
flexibility that represents the maximum resilience of
the process to tolerate uncertainties while still being
capable of operation.
E. N. PISTIKOPOULOS~ and T. A. MAZZUCHI
Koninklijke/Shell-Laboratorium (Shell Research B.V.), P.O. Box 3003, 1003

int. j. prod. res., 2002, vol. 40, no. 16, 4111±4130
Flexibility analysis: a methodology and a case study
Y. KAHYAOGLU{*, S. KAYALIGIL{ and J. A. BUZACOTT}
A methodology for analysing manufacturing ¯exibility is proposed. A real-life
case is discussed to demonstrate the proposed methodology. The case involves the
grinding operations of an engine manufacturer. As an integral part of the methodology,
statistical analyses using response surface methodology are carried out.
Potential applications of the proposed methodology are discussed. Planning
models and ¯exibility measure used are outlined in the appendices.
1. Introduction
A methodology for conducting a ¯exibility analysis is presented here on the basis
of an operational approach to measuring manufacturing ¯exibility. Such an
approach embodies the description of system operations in terms of the capabilities
of the system to handle a speci®ed set of environmental changes, ensuring that
¯exibility of operations relates to the overall competitiveness of the ®rm. The methodology
enables an in-depth analysis of how manufacturing system ¯exibility is
exploited using factors speci®ed with respect to the con®guration of the system,
the planning model used and/or environmental changes. The proposed ¯exibility
analysis methodology (FAM) o€ ers an analytical tool for evaluating the behaviour
of the ¯exibility of a given manufacturing system. FAM o€ ers insight for management
on issues such as (1) e€ ective (current) use of capabilities in dealing with
environmental changes, (2) possible improvements in system ¯exibility by modifying
machine operations, such as undertaking set-up improvements, and (3) levels of
the con®guration attributes and environmental changes for which the ¯exibility
potential of the manufacturing system is maximized.

Business strategy, manufacturing flexibility and organizational performance relationships: a path analysis approach

In Japan, technology spillovers have been less successful in the 1990s than they were in the 1980s. One apparent reason for this is a decline in institutional flexibility-the ability of organisations to absorb technology, transform human capital and adapt to changing global conditions. Information and communication technology (ICT) has become embedded in US business practice, but Japanese firms have yet to absorb ICT or respond to human capital needs. This lack of flexibility has had a significant negative impact on the vitality of the Japanese economy. Section 2 of this paper demonstrates recent changes in Japan's institutional flexibility by contrasting technology spillovers of the 1970s and 1980s with those of the 1990s, linking this institutional flexibility with R&D diversification and showing the negative impact on Total Factor Productivity and GDP. This analysis was performed using data compiled by the Tokyo Institute of Technology as well as data from surveys conducted by a number of Japanese government offices and agencies. Section 2 also discusses Japan's 'dual economy' by looking at key differences between small and medium-sized enterprises (SMEs) and large enterprises (LEs) in terms of labour rigidity and ICT penetration. These differences are one aspect of institutional flexibility. Section 3 starts by comparing the economic growth rates in Japan and the USA in the second part of the 1980s and the first part of the 1990s. A comparison of labour, capital, material and Total Factor Productivity indicates a decline in flexibility in Japan and an increase in flexibility in the USA. Additionally, this reversal can be seen in technology, labour and capital substitution. Section 4 discusses key changes in the US and Japanese organisational environments as they converge on different digital platforms and implications for their respective institutions. Key questions are raised regarding often over-simplified fundamental changes purported in the USA. In this regard, the truly 'innovative' nature of SMEs in the USA is questioned as institutional rigidity in this sector grows. Section 5 summarises final implications of this analysis and directs future work towards questions arising from this study

Technology spillovers and economic vitality: an analysis of institutional flexibility in Japan with comparisons to the USA

Analytical tools are presented for assessing the performance of complex multiproduct systems by explicitly accounting for potential interactions between different subsystems in the additional presence of continuous parameter uncertainty. For practical purposes this means evaluating the ability of processing systems to simultaneously handle continuous uncertainty (product demand, feedstock qualities, etc.) and discrete-state uncertainty (equipment availability). First, a stochastic flexibility index is proposed to measure the probability that a given design is feasible to operate in the presence of continuous uncertainty. Then, by considering the effect of equipment failures on the process flexibility, a combined flexibility-reliability index is introduced. Finally, taking into account the effect of maintenance and equipment repair time on equipment availability, a combined flexibility-availability index is introduced

Flexibility, reliability, and availability analysis of manufacturing processes: a unified approach

Analysis of flexibility for batch distillation columns
The growing interest in multipurpose units in the last years is due to its use in biotechnologic and fine chemical processes. The flexibility must be an intrinsic characteristic of these process units. In this work a performance analysis of multicomponent batch distillation for the separation of various mixtures with different thermodynamic characteristics was studied. After a rigorous modelling, a software was developed to simulate a batch distillation process. This program allows the choice of many thermodynamic models to obtain the separation of the mixture, using conventional batch distillation (rectifying column) or inverted batch distillation (stripping column). Due to the fact that rigorous modelling of this process generates a stiff system of ordinary differential equations, a reliable semi-implicit method of numerical integration was employed to quickly solve this system. Beyond thermodynamic characteristics, it is also important the analysis of the different operating conditions involved (different initial composition of still, reflux ratio, reboiler duty, etc.), since they are directly connected to the study of column flexibility. The influence of these modifications on the column productivity was also explored


Exploring flexibility and execution competencies of manufacturing firmsNarasimhan, R. (Dept. of Marketing & Supply Chain Manage., Michigan State Univ., East Lansing, MI, USA;); Talluri, S.; Das, A. Source: Journal of Operations Management, v 22, n 1, Feb. 2004, p 91-106ISSN: 0272-6963 CODEN: JOTMES Publisher: Elsevier, Netherlands Abstract: Manufacturing flexibilities improve a firm's ability to react to customer demands without incurring excessive time and cost penalties. While development of manufacturing flexibilities is desirable and indeed critical for some firms, exploiting the flexibility capabilities to achieve tangible firm-level performance outcomes through effective execution is becoming increasingly important. This paper presents a conceptual model that introduces two new constructs: flexibility competence and execution competence as distinct from manufacturing flexibility. Based on the proposed conceptual model and a multistage data envelopment analysis (MDEA) of empirical data, the roles of flexibility and execution competencies in determining performance are examined. The results indicate that some firms are more effective than others in exploiting investments in advanced manufacturing technologies and strategic sourcing initiatives to develop manufacturing flexibilities. Thus, lending credibility to the new construct referred to as flexibility competence. We also conclude that some firms are more effective than others in converting manufacturing flexibilities into tangible firm-level performance, suggesting that execution competence is an important construct that needs attention. We suggest future research in this area for comprehensively investigating these two new constructs proposed in this paper and identifying the factors that influence them (60 refs.)



Accession number:
7942866
Title:
Flexibility analysis in implementation of mass customization
Authors:
Wu Nai-qi; Yu Zhao-qin
First author affiliation:
Sch. of Mechatronics Eng., Guangdong Univ. of Technol., Guangzhou, China
Serial title:
Computer Integrated Manufacturing Systems
Abbreviated serial title:
Comput. Integr. Manuf. Syst. (China)
Volume:
9
Issue:
9
Publication date:
Sept. 2003
Pages:
797-802
Language:
English
ISSN:
1006-5911
CODEN:
JJZXFN
Document type:
Journal article (JA)
Publisher:
Editorial Department of CIMS
Country of publication:
China
Material Identity Number:
H893-2003-011
Abstract:
It is a trend for enterprises to implement the mass customization to meet the customer's demands and win the global competition. So it is necessary to do the manufacturing process reengineering, a involving high risk. Flexibility is very important for advanced manufacturing systems, especially for the systems that implement the mass customization. Based on the flexibility analysis, an approach is proposed to do the manufacturing process reengineering for mass customization in this paper. A case study is also presented to show the application of the proposed approach
Number of references:
22
Inspec controlled terms:
customer satisfaction flexible manufacturing systems manufacturing processes product development
Uncontrolled terms:
mass customization manufacturing process reengineering advanced manufacturing systems flexibility analysis
Inspec classification codes:
C7480 Production engineering computing E1510 Manufacturing systems E1400 Design E0120R Customer services
Treatment:
Practical (PRA); Experimental (EXP)
Discipline:
Computers/Control engineering (C); Manufacturing and production engineering (E)
Database:
Inspec
Copyright 2004, IEE



Introduction
Although ¯ exibility has been recognized as a competitive weapon in international
and domestic marketplaces, researchers are still confused in de® ning the meaning of
manufacturing ¯ exibility (Chung and Chen 1990). Managers, moreover, are still
unable to understand clearly how to implement it when they have to cope with an
uncertain environment (Slack 1989). In order to explain the confusion, Swamidass
(1988) stated that three problems were caused in the literature, namely: (1) the overlapping
of the concept, (2) aggregation of terms in some other terms, and (3) identical
terms with diOEerent meanings.
Researchers have tried to refocus the concepts of manufacturing ¯ exibility;
nevertheless, there still exists a lack of any comprehensive and integrated treatment
on measurement of manufacturing ¯ exibility. The concepts are either incomplete or
too abstract for operational applications; moreover, the measurements are somewhat
too simple to cover the whole concept of ¯ exibility or lack thorough consideration
(Ettile 1988, Sethi and Sethi 1990, Chen and Chung 1996). Consequently, the understanding
and suitable guidance for improving a system’s performance when coping
with an uncertain environment are blurred. This creates di culties for a ® rm when
setting manufacturing ¯ exibility as its competitive priority.

int. j. prod. res., 2001, vol. 39, no. 8, 1589± 1601
An approach to the measurement of single-machine Xexibility
AN-YUAN CHANGy*, DAVID J. WHITEHOUSEz,
SHENG-LIN CHANG} and YI-CHIH HSIEHy



Flexibility analysis and optimization of chemical plants with uncertain parameters
G. M. Ostrovsky, Yu. M. Volin, E. I. Barit and M. M. Senyavin Karpov Institute of Physical Chemistry, U. Obukha 10, 103064, Moscow K-64, Russia Received 17 June 1992. Available online 27 July 2001.
The problem of chemical plant (CP) optimization
under uncertainty has received increasing attention
in the literature (Takamatsu et al., 1973; Grossmann
and Sargent, 1978; Halemane and Grossmann,
1983; Swaney and Grossmann, 1985; Palazoglu and
Arkun, 1987).
There are the following sources of uncertainty in
the problem:
(1) an initial inaccuracy of coefficients in mathematical
models;
(2) a change of some coefficients in mathematical
models during plant operation;
(3) variations in ambient conditions.
On the other hand for any CP there exist conditions
which ensure its flexibility (absence of breakdowns
and harm to the environment, preservation
of a specified capacity and so on).
Mathematically these conditions can be described
by
r#i(d,z,fl)=ZO,i=l ,... m (I)
where d is a s-vector of design variables, z is a
vector of control variables, 9 is a r-vector of uncertain
parameters. The region T of a variation of the
uncertain parameters B is given by
T={9: eSeSeB>. (2)
One of the problems of the analysis and optimixation
of CP consists of determining such conditions of
the plant operation, which ensure the preservation
of its capacity for work under any variations of the...........