'Soft' systems thinking and information systems: a framework for client-led design

Abstract. Since the mid-1980s there has been a growing interest in the application of soft systems methodology (SSM) to the information systems design process. This interest has resulted from attempts to overcome the recognized deficiencies of conventional computer systems analysis methods and techniques. A particular problem which has received attention over the past 5 years is the epistemological and operational differences between the investigative process of the pre-design stage and the technological specification. We suggest that this argument is somewhat unproductive and advocate a necessary rethinking about the nature of information systems and the use of technology to support their activities. A re-evaluation of the way that we set about designing computer-based information systems suggests that many of the problems of conventional systems analysis methods may be alleviated by an approach that allows the 'client', or 'user', to have a greater control over the identification, specification and development of their information system(s). The authors' belief in this course of action has led to the development of client-led design as an underpinning philosophy for user participation in the design of computer-based information systems. Client-led design draws upon and develops concepts and tools from 'interpretive', or 'soft', systems thinking and, in particular, can be seen as providing a framework for the type of subjective inquiry that Checkland & Scholes (1990) referred to as 'ideal-type' mode 2 SSM. This paper is related to the papers published in the Journal of Information Systems (Vol. 3, No. 3), which was a special edition to illustrate the influence of 'soft' systems thinking upon information systems design and development.     

Using the theory of constraints thinking processes to complement system dynamics' causal loop diagrams in developing fundamental solutions

Standard OR/MS methods mainly focus on ‘hard’ aspects of problems represented by quantitative or mathematical formulations. Organisational settings typically pose challenges in the use of such methods, in that they may be inadequate to capture the ‘softer’ issues surrounding human behaviours, organisational practices and policies. Over the last 20 years, a number of ‘soft OR’ tools, methods and methodologies have emerged as a means of addressing such challenges, and in this paper, we selectively examine how such methodologies can complement hard and other soft methods. In particular, we examine the potential contribution of the theory of constraints (TOC) and system dynamics (SD) to multi‐methodological intervention. We begin by discussing their philosophical underpinnings in relation to other OR/MS methods, and by exploring how such an understanding can provide a theoretical basis for mixing methodologies and for their complementary use. Then, using a case suitable for classroom discussion, the paper provides insights into how the systemic qualities of selected TOC methods and tools may be harnessed in multi‐methodological intervention by identifying the communality and complementarity of TOC and other hard and soft OR/MS approaches to problem solving, in particular, the causal loop diagramming method of SD.     

Robustness analysis of uncertain discrete‐time systems with dissipation inequalities and integral quadratic constraints

This paper presents a connection between dissipation inequalities and integral quadratic constraints (IQCs) for robustness analysis of uncertain discrete‐time systems. Traditional IQC results derived from homotopy methods emphasize an operator‐theoretic input–output viewpoint. In contrast, the dissipativity‐based IQC approach explicitly incorporates the internal states of the uncertain system, thus providing a more direct procedure to analyze uniform stability with non‐zero initial states. The standard dissipation inequality requires a non‐negative definite storage function and ‘hard’ IQCs. The term ‘hard’ means that the IQCs must hold over all finite time horizons. This paper presents a modified dissipation inequality that requires neither non‐negative definite storage functions nor hard IQCs. This approach leads to linear matrix inequality conditions that can provide less conservative results in terms of robustness analysis. The proof relies on a key J‐spectral factorization lemma for IQC multipliers. A simple numerical example is provided to demonstrate the utility of the modified dissipation inequality. Copyright © 2016 John Wiley & Sons, Ltd.     

FUZZY SYSTEMS: BASIS FOR A MODELING METHODOLOGY?

Modeling becomes a key methodological issue when we have to deal with large, complex and ill-structured problems. The traditional analytic approach to modeling aims at capturing the aggregate logic of a problematic situation, which is taken to represent the essence of the problem. The aggregate logic does not, and should not, describe the full complexity of the modeling situation, but should give a sufficient basis for finding an optimal solution to the problem. In recent criticism, however, it is pointed out that the analytic approach does not give an adequate basis for solving complex and ill-structured problems, and a systems approach is recommended. Checkland finds that the so-called hard systems thinking is no better than the analytic approach and introduces a soft systems methodology. In this paper a fuzzy systems approach is found to be more flexible than the analytic and the hard systems methods, but more precise and easier to validate than the soft systems approach.     

Stable inversion of LPTV systems with application in position-dependent and non-equidistantly sampled systems

Many control applications, including feedforward and learning control, involve the inverse of a dynamical system. For nonminimum-phase systems, the response of the inverse system is unbounded. For linear time-invariant (LTI), nonminimum-phase systems, a bounded, noncausal inverse response can be obtained through an exponential dichotomy. For generic linear time-varying (LTV) systems, such a dichotomy does not exist in general. The aim of this paper is to develop an inversion approach for an important class of LTV systems, namely linear periodically time-varying (LPTV) systems, which occur in, e.g. position-dependent systems with periodic tasks and non-equidistantly sampled systems. The proposed methodology exploits the periodicity to determine a bounded inverse for general LPTV systems. Conditions for existence are provided. The method is successfully demonstrated in several application cases, including position-dependent and non-equidistantly sampled systems.     

平行系统方法与复杂系统的管理和控制

提出平行系统方法的基本思想、概念和运行的基本框架，并讨论了控制系统与平行系统的关系和异同之处，平行系统是控制系统和计算机仿真随着系统复杂程度的增加以及计算技术和分析方法的进一步发展而必然迈上的一个更高的台阶，是弥补很难甚至无法对复杂系统进行精确建模和实验之不足的一种有效手段，也是对复杂系统进行管理和控制的一种可行方式。     

Transient tracking performance improvement for nonlinear nonminimum phase systems: an additive-state-decomposition-based control method

To study the problem of improving transient tracking performance for nonlinear systems, this paper proposes an additive-state-decomposition-based control method for a class of nonlinear nonminimum phase (NMP) systems. This method ‘additively’ decomposes the original problem into two more tractable problems, namely a tracking problem for a linear time-invariant NMP ‘primary’ system and a state stabilisation problem for a certain nonlinear ‘secondary’ system. Then, controller for each system is designed respectively by employing existing methods, i.e. the linear quadratic regulator (LQR) method for the primary system and the backstepping method for the secondary system. Next, these two controllers are combined together to achieve the original tracking goal. Furthermore, the adjustment of weighting matrix Q in the LQR regulates the transient response of the closed-loop nonlinear system. Finally, two illustrative examples are provided to demonstrate the effectiveness of the proposed method.     

Elastic memory: Buddy systems interface

To implement single-ended flexible arrays (‘elastic memory’) a class of underlying dynamic storage allocation methods called buddy systems may be used to allocate fixed blocks of memory of restricted choices of size. Arrays are implemented in one approach as contiguous blocks of memory and in another as two-level structures. Each approach is combined with three buddy methods for allocating blocks of memory, making six methods in all. This paper illustrates the general ideas of implementing elastic memory mechanisms in terms of the buddy system interface.     

Less conservative robustness analysis of linear parameter varying systems using integral quadratic constraints

This paper considers the robustness of a feedback connection of a known linear parameter varying system and a perturbation. A sufficient condition is derived to bound the worst‐case gain and ensure robust asymptotic stability. The input/output behavior of the perturbation is described by multiple integral quadratic constraints (IQCs). The analysis condition is formulated as a dissipation inequality. The standard approach requires a non‐negative definite storage function and the use of ‘hard’ IQCs. The term ‘hard’ means that the IQCs can be specified as time‐domain integral constraints that hold over all finite horizons. The main result demonstrates that the dissipation inequality condition can be formulated requiring neither a non‐negative storage function nor hard IQCs. A key insight used to prove this result is that the multiple IQCs, when combined, contain hidden stored energy. This result can lead to less conservative robustness bounds. Two simple examples are presented to demonstrate this fact. Copyright © 2016 John Wiley & Sons, Ltd.     

Why situational method engineering is useful to information systems development

Effective methods and methodologies for building information systems (IS) remain crucial to building successful IS. This paper investigates the use of situational method engineering for IS development (ISD) projects in a professional bureaucracy. This specialist organization methodology (SOM) is built starting with the philosophy of ISD moving through to flexible, amethodical implementation methods, a proposed instance of situational method engineering that is targeted towards professional bureaucracies. An in‐depth philosophical discussion of the ontological, epistemological, research methodological and ethical underpinnings of SOM are outlined, in addition to its limitations, to develop the building blocks of a methodology to implement within a professional bureaucracy organization ISD scenario. Amethodical ISD will be introduced as the appropriate way to implement this developed methodology to build a successful IS. The contribution of this paper is to detail how to develop a philosophically consistent methodology for a specific organizational environment (in this case, using the specific organizational example of a professional bureaucracy) that, when combined with developers and tools, can create a method to be applied to build an IS that has a greater possibility of successful organizational adoption than an IS built using a method devised using more common IS method engineering approaches.     

Stability analysis and design of reset control systems with discrete-time triggering conditions

In a reset control system, reset actions are usually triggered whenever a continuous signal crosses a hyperplane. In the computer-based implementation, however, the continuous triggering signal is sampled and the triggering condition is then replaced by a discrete-time counterpart. In this work, we are concerned with the stability analysis and design of reset control systems based directly on discrete-time triggering conditions. First, a relationship between reset control systems and switched systems is established and some stability criteria are then obtained. Second, it is revealed through an example that a well-designed reset control system can be regarded as a hybrid system combining an underdamped baseline system with an overdamped reset mode. The reset matrix, which is assumed to be zero in general, can be adjusted to increase the damping ratio and thus further improve the transient performance. Based on this observation, a design guideline for single-input and single-output (SISO) systems is proposed. Lastly, a hard disk drive example is investigated to demonstrate the proposed design procedure.     

Further results on iterative learning control with convergence conditions for linear time-variant discrete systems

This article is concerned with some further results on iterative learning control (ILC) algorithms with convergence conditions for linear time-variant discrete systems. By converting two-Dimensional (2-D) ILC process of the linear time-variant discrete systems into 1-D linear time-invariant discrete systems, this article presents convergent ILC algorithms with necessary and sufficient conditions for two classes of linear time-variant discrete systems. Main results in (Li, X.-D., Ho, J.K.L., and Chow, T.W.S. (2005), ‘Iterative Learning Control for Linear Time-variant Discrete Systems Based on 2-D System Theory’, IEE Proceedings, Control Theory and Applications, 152, 13–18 and Huang, S.N., Tan, K.K., and Lee, T.H. (2002), ‘Necessary and Sufficient Condition for Convergence of Iterative Learning Algorithm’, Automatica 38, 1257–1260) are extended and generalised.     

Designing sociotechnical systems with cognitive work analysis: putting theory back into practice

Cognitive work analysis (CWA) is a framework of methods for analysing complex sociotechnical systems. However, the translation from the outputs of CWA to design is not straightforward. Sociotechnical systems theory provides values and principles for the design of sociotechnical systems which may offer a theoretically consistent basis for a design approach for use with CWA. This article explores the extent to which CWA and sociotechnical systems theory offer complementary perspectives and presents an abstraction hierarchy (AH), based on a review of literature, that describes an ‘optimal’ CWA and sociotechnical systems theory design system. The optimal AH is used to assess the extent to which current CWA-based design practices, uncovered through a survey of CWA practitioners, aligns with sociotechnical systems theory. Recommendations for a design approach that would support the integration of CWA and sociotechnical systems theory design values and principles are also derived.     

Socio-technical systems: From design methods to systems engineering

It is widely acknowledged that adopting a socio-technical approach to system development leads to systems that are more acceptable to end users and deliver better value to stakeholders. Despite this, such approaches are not widely practised. We analyse the reasons for this, highlighting some of the problems with the better known socio-technical design methods. Based on this analysis we propose a new pragmatic framework for socio-technical systems engineering (STSE) which builds on the (largely independent) research of groups investigating work design, information systems, computer-supported cooperative work, and cognitive systems engineering. STSE bridges the traditional gap between organisational change and system development using two main types of activity: sensitisation and awareness; and constructive engagement. From the framework, we identify an initial set of interdisciplinary research problems that address how to apply socio-technical approaches in a cost-effective way, and how to facilitate the integration of STSE with existing systems and software engineering approaches.     

Rethinking ‘IT/IS use in a technological mature society’ from the actuality point of view: critical learning in reflection on SSM meeting about ‘IT/IS use’

The history of the human-centered system movement (Gill in AI Soc 10(2), 1996) tells us that information technology (referred to as IT below) has come to dominate our life-world or societal functions. Since from 1990s, its streaming influence could be called ‘abnormal.’ Since entering the twenty-first century, the IT system has been on automatic acceleration and has been spreading more and more rapidly to many facets of our lives. In many sectors, this ubiquitous streaming of IT is seen to be central to societal development, and in a Japanese sense, IT could be seen as a resource to realizing technologically a mature society. This trend of IT seems to be unstoppable. In this sense, IT dominance can be regarded as abnormal to the point that IT-centered information systems (referred to as IS below) fall far short of the deep appreciation of the complex and diverse life needs of people and societies, and this leads to the implementation of IT/IS from technological perspective, with a belief that everything, which we can do could be and should be, done now by IT/IS. However, as IT/IS have become to be embedded in many facets of societies and are influencing over our everyday life, we need to examine them not from the point of ‘capability’ but ‘allowability,’ in other words, not from the perspective of technology (cognition), but from the prospective of intuition and feeling of actual life (action). We term reality as seen in the narrow sense of cognition and actuality as seen in terms of action (Uchiyama in Theory and practice of actuality, Daito Bunka University, Tokyo, 2003). We draw a distinction between the two classes of ‘IT/IS’ systems, those which belong to the ‘reality’ and those which belong to the ‘actuality.’ To appreciate this distinction, we propose that this requires not only an understanding of the design of these IT systems but of the methodology of their use and their evaluation. To carry out the process of evaluation of IT/IS systems, we need to develop a new ‘appreciation’ methodology which enables us to rethink ‘IT/IS’ as ‘A system to use IT/IS.’ This idea is similar to the idea of Beck’s (World risk society theory (trans: Shimamura K), Chikuma Scholastic Collection (in Japanese), 2010) reflecting the modern. So, we propose a strict distinction between the two systems classes of ‘IT/IS’ which we call belonging to the ‘reality’ and ‘A system to use IT/IS’ which we call belonging to the ‘actuality.’ The methodology to deal with ‘actuality’ has not yet been developed, but Checkland and Poulter’s (Learning for action, Wiley, New York, 2006) soft systems methodology (referred to as SSM below) intends to deal with this kind of class of systems, that is, ‘human activity systems.’ He uses the key concept of ‘accommodation’ which means ‘to live with different individual world views based on sharing of actuality,’ and thus, he proposes to overcome the idea of consensus which is the agreement with the ‘reality’ level. In this paper, we adopt a methodology based on the SSM’s accommodation and not based on the consensus on the ‘reality’ level. By using such a methodological thinking, we reconsider the problem of evolving technologically a mature society which can be seen as a problem relevant to ‘A system using IT/IS’ rather than the problem of IT/IS itself. In doing so, we could draw some innovative orientations in the field of IT/IS which by traditional methodology could not be drawn. It is not certain whether our attempt could make a difference to the runaway of IT/IS. We illustrate this purpose by studying a workshop process which highlights that even participating experts of IT/IS themselves felt apprehensive about the more and more focus on the implementation of IT/IS solutions both in the present and the future. We believe that the first step toward this purpose is to explore the new orientation of IT/IS use. The aim of this first step is to make a difference to the ‘abnormal’ situation and hope to create a foothold for the reorientation of ‘A system to use IT/IS.’     

The Role of OR in Information Systems Strategy Development

Some of the most inspiring OR successes in World War II addressed the deployment of new technology into military operations. Today information technology has strategic implications for most if not all organisations. In addition to their structuring and analytical expertise, OR practitioners have developed skills of intervention, knowledge of how organisations work and experience of implementing change. OR should therefore have much to contribute to information systems strategy development and implementation but there is little evidence of activity in the U.K. at least. The paper considers why this might be the case and challenges the OR community to get involved before it is too late. This lack of activity in the U.K. is particularly surprising given the development of an interest in ‘soft’ OR methods, which are well suited to the development of information systems strategy. As an example, the contribution of ‘soft’ OR methods to the development of an IS strategy for a large retailing chain is described.     

Reasons for bottlenecks in very large-scale system of systems development

ContextSystem of systems (SoS) is a set or arrangement of systems that results when independent and useful systems are to be incorporated into a larger system that delivers unique capabilities. Our investigation showed that the development life cycle (i.e. the activities transforming requirements into design, code, test cases, and releases) in SoS is more prone to bottlenecks in comparison to single systems.ObjectiveThe objective of the research is to identify reasons for bottlenecks in SoS, prioritize their significance according to their effect on bottlenecks, and compare them with respect to different roles and different perspectives, i.e. SoS view (concerned with integration of systems), and systems view (concerned with system development and delivery).MethodThe research method used is a case study at Ericsson AB.ResultsResults show that the most significant reasons for bottlenecks are related to requirements engineering. All the different roles agree on the significance of requirements related factors. However, there are also disagreements between the roles, in particular with respect to quality related reasons. Quality related hinders are primarily observed and highly prioritized by quality assurance responsibles. Furthermore, SoS view and system view perceive different hinders, and prioritize them differently.ConclusionWe conclude that solutions for requirements engineering in SoS context are needed, quality awareness in the organization has to be achieved end to end, and views between SoS and system view need to be aligned to avoid sub optimization in improvements.     

Simple saturated designs for ANCBC systems and extension to feedforward nonlinear systems

This article re-examines the robust stabilisation of the asymptotically null-controllable with bounded controls (ANCBC) systems, and extends the established algorithm to a wide class of feedforward nonlinear systems whose nominal dynamics contains both multiple integrators and multiple oscillators. Based on the notion of ‘converging-input bounded-state’ (CIBS) rather than ‘small-input small-state’ (SISS), the computation burden in Sussmann et al. (Sussmann, H.J., Sontag, E.D., and Yang, Y. (1994), ‘A General Result on the Stabilization of Linear Systems using Bounded Controls’, IEEE Transactions on Automatic Control, 39, 2411–2425) is reduced and a class of simple saturated control laws is presented for the CIBS stabilisation of ANCBC systems. Then, by combining the technique of dealing with higher-order terms, the algorithm for ANCBC systems is extended to feedforward nonlinear systems.     

The application of an expert system shell to an unstructured domain of expertise: using expert system technology to teach SSM

Action research is orchestrated by the interaction between theory and practice as exemplified by soft systems methodology (SSM). The use of computers has traditionally been developed out of what has been referred to as the ‘rationalistic’ tradition which represents the search for solutions for pre-determined, logical goals (Winograd & Flores, 1986). Action research anticipates the need to explore and learn about each intervention into human activity, using models thought to be relevant to thinking about the world to help structure the learning process. In comparison, the ‘rationalistic’ tradition seeks universal laws for behaviour and uses validated models of the reality represented by these laws to solve problems. It would seem, therefore, that to translate SSM into a computer-based format would be dialectically opposed to the intellectual framework in which the methodology is seated. However, the authors suggest that there is one area in which a computer-based version of SSM may be useful. This paper describes an exploratory study of the application of expert system technology as an aid to teaching SSM.