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CONTEXT: Residents need their supervisors in the operating room to inform them on how to use their expertise in present and future occasions. A few studies hint at such explicit teaching behaviour, however without explaining its underlying mechanisms. Understanding and improving explicit teaching becomes more salient nowadays, as access of residents to relevant procedures is decreasing, while end-terms of training programs remain unchanged: high quality patient care.OBJECTIVES: A structured analysis of 1. The practices supervisors use for explicit teaching and 2. How supervisors introduce explicit teaching in real time during surgical procedures.METHODS: An observational qualitative collection study in which all actions of nine supervisor-resident dyads during a total hip replacement procedure were videotaped. Interactions in which supervisors explicitly or implicitly inform residents how to use their expertise now and in future occasions were included for further analysis, using the iterative inductive process of conversation analysis.RESULTS: 1. Supervisors used a basic template of if/then rules for explicit teaching, which they regularly customized by adding metaphors, motivations, and information about preference, prevalence and consequence. 2. If/then rules are introduced by supervisors to solve a (potential) problem in outcome for the present patient in reaction to local circumstances, e.g. what residents said, did or were about to do.CONCLUSIONS: If/then rules add the why to the what. Supervisors upgrade residents' insights in surgical procedures (professional vision) and teach the degree of individual freedom and variation of their expert standards for future occasions. These insights can be beneficial in improving supervisors' teaching skills.

This article reflects on the investigations that have driven research projects, student designs and collective endeavours in Advanced Landscape and Urbanism research group at the University of Greenwich. The article sets out three frames: Firstly, an emphasis on landscapes being socially constructed through interrelations between individuals, people and the worlds they produce. Secondly, an embrace of diversity of landscape approaches, resulting in projects created from unique combinations of experiences, methods, skills and ambitions – but differentiated through focused research projects and structured design studios. Third, an embrace of tensions within and between landscapes, working with the complexities and contradictions that landscapes entail, as much as with the potential agency of landscape relations.

The present study explores the phenomenon of remixing in product design for additive manufacturing (AM). In contrast to other manufacturing techniques, AM offers unprecedented flexibility in adapting existing product designs to changing requirements. However, in order to benefit from this potential, structured design procedures and tools are indispensable. As a possible solution, online platforms for collaborative 3D model creation are increasingly implementing features for remixing, a concept describing the creation of new models on the foundation of existing design elements. Against this backdrop, the objective of this research is to provide evidence for the value of remixing as an organizational intervention for improving product design processes. To this end, we present a mixed methods approach using data from Thingiverse, the world's largest AM-related online community. In a first step, we investigate qualitative data from 81 individual remix-based designs to identify the underlying mechanisms of remixing. We identify six such mechanisms that can further be grouped by the intended outcome of the respective process (creativity-oriented: inspiration, play, learning; productivity-oriented: speed, improvement, empowerment). In a second step, we turn to a quantitative analysis of platform data, which indicates that remixing may lead to better design process outcomes in terms of quantity and diversity of designs. Furthermore, we find that designs created by remixing designers are significantly more often printed by community members suggesting that remixing helps ensure manufacturing compatibility akin to continuous process improvement. Our research has several implications for individual designers and organizations engaging with product design for AM.

This paper presents a systematic robust control framework based on the structured H∞ approach to address the synthesis of the atmospheric ascent-flight control system of a launch vehicle. To introduce this synthesis framework, the control problem is first formulated to recover the classically designed baseline rigid-body controller of the actual VEGA launcher VV05 mission. This legacy recovery builds the necessary background for a good understanding of the problem and increases confidence for its transfer to the Space industry. Subsequently, it is shown how to systematically augment the robustness of the design from the synthesis stage against wind turbulence perturbations and parametric uncertainty. The resulting controller is verified via classical stability margins and robust structured singular value analyses and finally validated using nonlinear, time-domain simulations in a Monte Carlo campaign. It is highlighted that this robust synthesis framework allows to obtain a controller with improved robust stability and global performance, and more importantly, it provides a more systematic methodology for design.

The hybrid architecture still be the most attractive solution for the analog‐digital beamforming in millimeter wave (mmWave) large‐scale multiple input multiple output (LS‐MIMO) systems, s...

Systems engineering methodology has expanded its application fields into creating innovations and designing societal systems. In the present age, where everything has increased in complexity, systems engineers are challenged to solve ill-defined problems to create innovations and to design societal systems. Design thinking has attracted attention as a methodology for solving ill-defined problems. However, design thinking cannot create innovations or design societal systems by itself. It is effective when it is applied to the systems engineering process, and embedded in its processes. This paper proposes using the advantages of both design thinking and systems engineering to build the Structured Design Thinking Framework as an extension to the DIKW model. The framework has integrated the non-structured design thinking process and the structured systems engineering process. We used this framework to redesign a local community in Japan and to design a new concept of aquarium, and confirmed that this framework works.

In neuroendocrinology, mathematical modelling is about formalising our understanding of the behaviour of the complex biological systems with which we deal. Formulating our explanations mathematically ensures their logical consistency, and makes them open to structured analysis; it is a stringent test of their intellectual coherence. In addition, however, modellers are seeking to extend our understanding in new ways, by seeking novel, simple explanations for complex behaviour. Here we discuss some styles of modelling as they have been applied to neuroendocrine systems, and discuss some of their strengths and limitations.

The current military pilot training system in the UK is struggling to train the required number of pilots economically and to the standard needed by military operations. Several factors are crippling the training including unrealistic training aircraft and a fragmented training structure. Currently there has only been limited structured analysis into pilot training, the current system has blindly evolved from cold war tactics/aircraft and is struggling to adapt to a changing world This paper presents a fresh approach to military training by understanding the base requirements and the effect of the changing environment over the medium term (10-20 years).

This paper considers the problem of assessing the induced L2 gain of a system composed of non-identical interconnected piecewise-linear subsystems, when the topology of the underlying graph is arbitrary. Blending tools inspired by dissipativity theory and the S-procedure, it presents sufficient conditions in the form of a set of finite-dimensional linear matrix inequalities which are coupled in a way that reflects the spatial structure of the system under analysis. Results are presented comparing the efficacy of the new conditions to similar conditions for an equivalent global piecewise-linear system. Copyright © 2007 John Wiley & Sons, Ltd.

Strategic flexibility, both in its conceptual and practical form, has often fallen prey to criticism for the failure to manifest itself in terms of concrete steps of application and structured design. Constant non-linear change, toying with managerial competence and emotional intelligence skills, aggravates and makes this discussion all the more pertinent. Quantification and analysis of strategic flexibility have been cumbersome to accomplish. This paper aspires to supplement the existing literature by defining strategic flexibility as indispensable in times of turbulence and ongoing change. A parallel drawn between organizations and living systems, and their resistance patterns to environmental shocks originating from change, will serve as a background platform to the discussion, as well as an argumentative tool towards refuting the allegation that flexibility in strategy formulation equates to lack of strategic orientation. Copyright © 2004 John Wiley & Sons, Ltd.

Object-oriented analysis and design methods are becoming predominant in the systems engineering workplace. One result is that object-oriented analysis (OOA) may come to replace older structured analysis (SA) methods traditionally used by systems engineers. Another result is that assertions are sometimes found in the literature claiming or implying that object-oriented analysis methods are uniformly better than structured analysis methods. But if OOA and SA are homeomorphic1, a systems engineer should choose to work with the analysis methods and representations that are most effective and convenient to solve specific problems of interest. A substantially complete invertible mapping is presented in this paper to serve as evidence that OOA and SA are homeomorphic. A characterization of the kinds of problems better suited to one domain than the other is included in the paper.

SUMMARY This article provides a structured analysis for conceptual and theoretical developments in the field of supply chain management. The article proposes a conceptualization of the supply chain problem domain called the “3S Model.” The model highlights three dimensions of interest to supply chain scholars and practitioners alike: the synthesis of the business and resources network; the characteristics of synergy between different actors in the network; and the synchronization of all operational decisions related to the control of the production and delivery of goods and services.

Two faculty in business and public and environmental affairs find that students need to move between personal-based experience, data, and a higher level of analytical reasoning. Their teaching of marketing and statistics is shown to benefit from the structured analysis and detailed assessments of the Decoding the Disciplines model.

A system supporting the refining of an analytical model in the upstream processes of software development has been developed. Compared with the absence of such support, human oversights during system analyses are reduced. Although applications and implementation support tools for downstream processes of software development have been vigorously conducted in the past, since there are many stages in studying the applications of support tools for upstream processes, especially structured analyses and the like, expression of concept models has received almost no support for the analytical processes themselves. SpecRefiner has been constructed as a means of supporting stepwise refinement in structured analyses. SpecRefiner is the system which supports a requested analysis process by storing statements of what is to be performed, in specifications written in natural language and the DFDs (data flow diagrams) accompanying them in a case base, and by detecting similar specifications and DFDs in the stepwise refinement process when performing a newly requested analytical task. The method treats the software development process as consisting of three steps, namely, finding, revising, and refining, and supports each step. It finds a past analyzed case, revises this case, and refines it. In addition, it supports asynchronous collaborative design by retaining design rationale or a design history. Fischer [3, 4] and Nakakoji [10] state that the construction of an application for an area or domain is facilitated by a specialist who constructs a domain-oriented design support environment by using this tool. In the study by Mizoguchi [9], ontology is organized in area-independent levels, and design using building blocks corresponding to the ontology is made possible by means of interviews between the SE and the end user based on the ontology. In the investigation of Seta and colleagues [13], the user himself describes the task configuration. The proposed scheme lies between the domain-oriented design environment of Fischer and the domain-independent ontology approach of Mizoguchi. The proposed scheme can reduce the cognitive overload of the end user or SE in translating the domain-oriented work and the implementation-level work by seamlessly connecting the domain-oriented knowledge and the domain-independent ontology or symbolic-level knowledge. As a result, the proposed scheme can use analytical time effectively by reducing human errors during analyses. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(6): 32–43, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10019

Many knowledge management (KM) efforts revolve around managing documents in a repository or enabling better real-time communication. An ideal approach would combine these with the ability to create knowledge content that can be either formal or informal in nature, in a rapid, real-time manner. We will call this Rapid Knowledge Construction (RKC). This paper describes the concepts underpinning our approach to RKC, and provides a case study of the approach in an industry context. The Compendium approach, which has been applied in projects in both industry and academic settings, facilitates the rapid creation of the content of a KM repository, by combining collaborative hypermedia, group facilitation techniques, and an analytical methodology rooted in knowledge acquisition and structured analysis. Compendium addresses key challenges for the successful introduction of KM technologies into work practice: (i)!customization for different use contexts; (ii)!integration of formal and informal communication; (iii)!integration of both prescribed and ad!hoc representations; (iv)!validation and cross-referencing of the repository ‘on the fly’ at the point of entry; (v)!conversion of organizational documents/emails into a hypertext database, and (vi)!conversion of hypertext databases into organizational document formats.

The area of information systems reliability assurance is taking on increasing importance as several professional accountancy bodies have adopted standards and criteria for assurance practices. This importance is compounded by the inevitability of a shift in future audit models to an empha-sis on information systems reliability. This paper looks at the conflicts that occur in attempting to use structured analysis to evaluate development processes that are often dynamic rather than static. Discussion then shifts to consideration of the unconscionable absence in both assurance models and development processes of consideration for the impact of technology implementations on individuals and society.

A UML-based process for developing C4ISR architectures is presented. The process demonstrates the feasibility of developing architecture descriptions that conform to the C4ISR Architecture Framework based on an Object-Oriented paradigm. The process is illustrated through the same example that is used in the companion paper to illustrate the Structured Analysis approach so that comparisons can be made. © 2000 John Wiley & Sons, Inc. Syst Eng 3: 288‐312, 2000

A Structured Analysis based process for developing C4ISR architectures is presented. The process demonstrates the feasibility of developing architecture descriptions that conform to the C4ISR Architecture Framework based on the Structured Analysis paradigm that underlies the concepts and definitions in the Framework. Furthermore, the process incorporates the derivation of an executable model that can reveal the logical, behavioral, and performance characteristics of the architecture. The complete process is illustrated through an example involving the insertion of a new technology in a large legacy system. © 2000 John Wiley & Sons, Inc. Syst Eng 3: 248–287, 2000

Functional analysis has been the traditional approach to modeling systems. Now that object-oriented analysis has essentially displaced structured analysis for software development, it is reasonable to ask whether objects should go on to replace functions for modeling at all levels of system definition. Issues related to modeling notations, methods, and resulting analytical flexibilities are discussed. While the object oriented notations and methods have grown significantly in the past few years, they may not yet be ready to replace functional analysis at the system level.

In model driven or model based experimentation, the model of the experiment is a key component of the closed loop model of the process. The model is created through interaction with the team designing the experimental organizations as well as the team creating the experimental environment. Starting with preliminary descriptions, the model evolves as more specific details are available and influences the final experimental design. The methodology used to design the model reflects both the types of design information available and the underlying hypothesis of the experiment. Experiments validating fixed types of structures or processes lead to a model designed with a Structured Analysis Design Technique which leads to an explicit but rigid model design. Experiments investigating adaptation require a more flexible model which can be created using an Object Oriented design approach. This leads to a more flexible, object view of the experimental design. Either approach leads to an appropriate set of models from which an executable model can be derived. The executable model is used to carry out simulations In order to analyze the dynamic behavior of the model, an input scenario must be created based on the actual inputs that will be used in the experimental setting. When the model is stimulated with the scenario, its behavior can be observed and its performance measured on different criteria. Because it is a computer simulation, input parameters can be varied, constraints can be relaxed, and other variables (possibly) affecting the hypotheses can be explored to see their effect on the model and by inference the experiment. These results can then be made available to the design teams to influence further iterations of the design. Indeed, the model allows the consideration of many excursions, a situation that is not possible when the experiments include teams of humans.

This paper presents the advantages of using a Stimulus Response Requirement Specification (SRRS) technique to reduce costs, development time, and errors in the generation of system level test cases in comparison to using a Structured Analysis (SA) technique. A SRRS technique describes requirements in terms of externally visible inputs (stimuli), processing, and externally visible outputs (responses). The SRRS techniques may be viewed as a general category of requirements specification techniques that are based on concepts originating in system test methods. Currently used, popular SRRS techniques include Use Cases and Scenario driven techniques. This paper first reviews a basic process for developing system test cases. An example from a library system is used to illustrate the first step of this process with a conventional SA requirements specification and a SRRS. The use of a SRRS technique to document the requirements specification simplifies the test case generation process by eliminating the first step in the three step process.

Product systems are created by process systems otherwise known as contractors, developers, suppliers, or enterprises. Owners of these process systems seldom consider themselves systems so they commonly fail to take advantage of the same powerful development process that they may be very proficient in applying to develop product systems to improve, develop, or re-engineer their own system. This paper offers some parallels between the structured analysis process applied for the purpose of developing product systems and the application of the same process for developing the enterprise. This application is then extended to couple the enterprise identity thus formed to multiple program planning suites through a seamless planning transform.

This paper presents a possible solution to the problem of identification of factors influencing long-term survival patients, using regression trees. The separation of the two classes of long-term survivors (cured patients) and of failed-to-cure patients is generalized to l* classes of survivors and is carried out via a latent variable, whose determinations are provided by the regression-tree classification. Two sets of factors are thus identified within the set of covariates: the factors influencing the prognosis and those influencing the survival classification (diagnostic factors). The relationship between the two sets is then explored, both theoretically and using an application to a data set of multiple myeloma patients. (C) 1998 John Wiley & Sons, Ltd.

The AIC (Automation and Integration in Construction) Research Group at the University of Salford is currently working on the development of a PC-based integrated environment prototype called SPACE (Simultaneous Prototyping for An integrated Construction Environment). SPACE aims to incorporate various construction applications, enabling project information to be shared between these applications and allowing the user to run them simultaneously, i.e., concurrent engineering. The purpose of this paper is to present the EVALUATOR [project Estimate and interim VALUation (monthly) generATiOn in an integRated environment] application of SPACE. EVALUATOR's main objectives are twofold : (1) to produce the project estimate in the form of an elemental bill of quantities (BQ) and (2) to generate monthly interim valuation certificates from the construction plan. Various structured analysis techniques have been implemented to model this application as an integral part of SPACE. The resulting Express-G (static data) and IDEFO (process) models are described. In addition, the sharing of information between EVALUATOR and the other relevant applications within the integrated environment is also discussed.

Mass customization is an established paradigm that aims at producing goods and services to meet individual customer's needs with near mass production efficiency. The implementation of the sustainable mass customization paradigm requires the development of a new business model that could reshape the way a company makes profit. Its implementation calls for a careful management of the transition process that interests the whole company and its supply chain. On the basis of the developed scheme that supports a structured analysis and the positioning of each considered element, it is possible to analyze and map the shift required to evolve to the sustainable mass customization, starting from the enabling tools needed, moving to the corresponding design activities and to the required interventions and the implications at managerial level.

The maintenance or re-engineering of a program usually begins with considerable effort in understanding the program structure. In this paper, an interactive tool for understanding the structure of non-object-oriented programs, known as the Object Finder, is presented. The structure of a program is defined in terms of the groupings of routines and data into modules within the program and the hierarchical relationships among the modules. The Object Finder incorporates two complementary approaches, one being top-down and the other bottom-up, to assist the software engineer in understanding the structure of a program based on the object-like features found in the program. In the top-down approach, the user obtains an overall understanding of the entire program as a collection of hierarchically organized objects. In the bottom-up approach, the user obtains a view of the information which is closely related to the components under examination. In both approaches, two methods are used to identify the objects in a program written in a non-object-oriented programming language. These methods identify sets of objects based on the data bindings and on the type bindings found in a program. An object is considered as a collection of routines, types, and/or data items of the program. The Object Finder combines the top-down and bottom-up approaches while using human input to guide the object identification process. Two examples of using this Object Finder are also presented to demonstrate the capabilities of the approaches to assist the software engineer in attaining a high-level understanding of the program structure.

There are many alternative areas where the benefits of systems engineering can be applied. One of the premier emerging areas of structured design today is in the design or redesign of social systems. The redesign of the education system, as a social system, is a prime candidate for the application of systems engineering. New Generation Education (NGE) is a systems engineering project to simultaneously redesign and evolve education. The unique balances this project requires within the processes and procedures of systems engineering can do much to teach us how to tailor our profession to other emerging applications.

Increasingly, the system engineer's primary function is to facilitate knowledge capture from a concurrent product team. This role increases the need for the systems engineer to architect a data environment that meets strict criteria for a structurally valid schema. An encompassing theoretical base for creating such data structures is currently unavailable to the practicing systems engineer. Starting with the “three view” schema of MIL-STD-499B, a data array paradigm based on elementary theories of sets and arrays is developed as a generally applicable structure. This paradigm is then demonstrated with several examples of structured systems engineering practice. These are compared with current practices and usage to test for errors. Conclusions reached are 1) That even at the level presented, this paradigm can assist systems engineers in improving their real-world practices; 2) Structured analysis should receive more attention in academic curricula for systems engineers; 3) Individuals knowledgeable in mathematical array and structural theories as well as systems engineering should contribute to a more complete body of formal theory; and, 4) Structural validity of the project schema should be regarded as a “first principle” for world-class systems engineering. Recommendations include suggestions for “best practices” groundrules that could be defined now, and speculation as to where expanded theoretical development should take place for maximum benefit to the industry.

Improved requirements traceability would result in significant cost savings since more requirements problems are due to failures in requirements management than failures in technical functions. Without adequate requirements traceability, errors are found late in system development and are expensive to repair. Our research identifies problems with industry's capability to trace product and process information, and offers some solutions1. We have defined a unique method, Concurrent Stimulus-Response Threads (CSRT), that traces complex system behavior. Based on CSRT and Entity-Relationship modeling, we make recommendations that will improve traceability in two requirements methods, Requirements Driven Design (RDD), and Real-Time Structured Analysis (RT-SA).

SUMMARY In this paper, we investigate into the feasibility of applying logic programming to structured design. We propose to use Prolog as a common machinery for the representation of various structured tools. We illustrate through examples how to produce structure charts from data flow diagrams, and evaluate them according to commonly recommended design guidelines. If the structure charts produced are not satisfactory, the inherent backtracking mechanism in Prolog will help to produce other versions for further evaluation.

To be competitive, companies must efficiently develop products that meet their customers' needs. Three established methodologies, Quality Function Deployment, Structured Analysis, and Concurrent Engineering combine to form a superpowerful technique to help companies be competitive. Quality Function Deployment (QFD) is a universally-used, powerful tool for relating the customer requirements to detailed engineering requirements. It is frequently referred to as “the voice of the customer”. Structured Analysis is a technique of systematically decomposing a system into progressively more detailed parts. A “picture oriented” method, this technique has a history of providing visibility into large systems. It is useful on small systems as well. Concurrent Engineering simultaneously deals with marketing, design and production concerns; traditional approaches treat each of these concerns separately. Concurrent Engineering emphasizes design for cost, design for manufacturing and assembly, design for serviceability, design for reliability, design for maintainability… in short, design for “X”. This emphasis on design for “X” begins at the very conception of the product. This paper describes how these three methods, QFD, Structured Analysis, and QFD interrelate and then describes a unique way to combine them into a supertool for assuring product competitiveness.

The overwhelming volume of requirements and specifications associated with large complex multi-disciplinary system development projects pose exceptional challenges to project engineers in their efforts to track and manage the hardware design response to the requirements and specifications. Previous systems engineering approaches using available methodologies and automated computer tools have been increasingly difficult to apply as the project complexity grows. Without effective methodologies and tools ensuring that system functional requirements are accurately interpreted and flowed down to the specification level has been difficult. Likewise, the allocation of functions to the architectural components, assemblies, and software including the interfaces among interacting systems has been hampered by inadequacy of conventional tools. This traceability extends to the identification of verification requirements associated with all elements of the system. The demand for increasingly complex systems, coupled by the ever-increasing sophistication of available supporting engineering and management tools, has spawned a variety of modern methodologies for addressing complex development tasks. These new paradigms, aided by powerful computer-based software tools, provide a structured development framework to: - Instill a disciplined focus on system engineering based on requirements - Establish a comprehensive, unambiguous path of trace-ability from top-level requirements to detailed design - Provide a common means for communicating complex system behavior to all program participants via graphical depictions - Develop a platform for the systematic support of the verification and test planning activities - Analyze the failure propagation behavior of the system for assessment of multiple failure modes and effects, safety and hazards analyses, redundancy management and failure tolerance - Create a simulation environment to study system behavior for analysis of performance, interfaces, and anomalies given a variety of hypothetical operational scenarios. This paper discusses the application of such a methodology, known as Enhanced Modern Structured Analysis (EMSA), which is being used in the analysis of the Space Station Freedom. The EMSA method has been derived from the methodologies of leading experts in the field of systems analysis, with suitable enhancements which were found necessary to accommodate the Space Station Program needs. The software to support this particular analysis is the RDD-100 (TM) package from Ascent Logic Corporation, as well as the Failure Environment Analysis Tool (FEAT) developed by Lockheed Engineering and Sciences Company. The hardware platform is an Apple Mactinosh IIfx(TM). Due to the prolific nature of general systems analysis, coupled with the power of a sophisticated computer platform and the flexibility of the methodology, this paradigm is recognized as having a wide applicability for analysis.

This paper presents lessons learned from an experiment to reverse engineer a program. A reverse engineering process was used as part of a project to develop an Ada implementation of a Fortran program and upgrade the existing documentation. To accomplish this, design information was extracted from the Fortran source code and entered into a software development environment. The extracted design information was used to implement a new version of the program written in Ada. This experiment revealed issues about recovering design information, such as, separating design details from implementation details, dealing with incomplete or erroneous information, traceability of information between implementation and recovered design, and re-engineering. The reverse engineering process used to recover the design, and the experience gained during the study are reported.

In this paper, a methodology for constructing hierarchical and structured predicate transition net specifications is developed, which includes new systematic notation extensions for supporting various transformation techniques upon predicate transition nets and several rules for applying such transformation techniques. The levelling technique in data-flow diagrams is adapted in the refinement and the abstraction techniques, and the state decomposition idea in state-charts is employed in designing various label formulation operators. The methodology is illustrated through the specification of a lift system. The methodology can significantly reduce the constructing complexity and enhance the comprehensibility of large predicate transition net specifications.

Structural change must not be misunderstood as only observing staffing levels or methods of organisation. On the contrary, the cost/benefit-relation is much more important. A balanced relation of a company's own personnel and the contractor's has to be considered. Structural change means also change of mind set: The task of management is nowadays to implement a culture of operational profit instead of a culture of demands. It is becoming more and more important to cooperate in a team. This cooperation starts early in defining the projects aims, includes analysing all functions, looking for alternatives regarding cost/benefit-aspects and is based on a clear, structured analysis of the problem instead of quick solutions

Certain types of computer language popular in areas such as decision support systems have the property that language statements need not be written in execution sequence, as the correct evaluation order can be established by dependency analysis. The uncontrolled use of these ‘nonsequential’ languages can lead to the development of programs and systems that are difficult to comprehend and maintain. This paper describes a method of clustering such code statements into sequential (procedural) modules to clarify visual presentation. The technique is based on depth-first search of directed graphs and will group those statements which are most strongly related to each other into a module.

The design and analysis of the structure of software systems has typically been based on purely qualitative grounds. In this paper we report on our positive experience with a set of quantitative measures of software structure. These metrics, based on the number of possible paths of information flow through a given component, were used to evaluate the design and implementation of a software system (the UNIX operating system kernel) which exhibits the interconnectivity of components typical of large-scale software systems. Several examples are presented which show the power of this technique in locating a variety of both design and implementation defects. Suggested repairs, which agree with the commonly accepted principles of structured design and programming, are presented. The effect of these alterations on the structure of the system and the quantitative measurements of that structure lead to a convincing validation of the utility of information flow metrics.

Amathematical programming clustering model that forms groups based on total group membership interactions is extended to include precedence relationships, group size limits, and group time limits. The extended clustering model is most appropriate for structured design of information systems as described by the computer-assisted process organization (CAPO), which requires certain ordering and may have limits on development and production capacity. An efficient algorithm for optimizing the CAPO criteria along with computational results is presented. The results show that the method is viable for the CAPO problems reported in the literature.

This paper describes a portable software tool used for the processing and maintenance of data flow diagrams which form the basis of structured analysis techniques. The tool itself is based on the idea that data flow diagrams can be modelled by means of semantic nets and can be manipulated by a semantic net processor. A major feature of the tool is the facilities it provides for the maintenance programmer.

The DTL language is the result of a combined study of data structured design methods and the use of concurrency as a high-level structuring device. Programs written in DTL are regarded as translations from input streams to output streams. Such translations are specified by the use of attributed translation grammars. This paper describes the implementation of DTL via an abstract virtual machine.

The use of a data-flow diagram and data dictionary for the requirements specification of an information management system is described together with the benefits to be gained from using prototypes. Construction of such prototypes in Ada is discussed in detail with a simple example being given. The use of a flexible user interface, generic data-flows, exception handlers for error conditions and a top-down design method that makes use of separate compilation indicates that Ada is an appropriate language for the development of such systems. Consideration is also given to the use of Ada in the construction of actual as well as prototype information systems.

A system development methodology is outlined before describing its application to the development of a microcomputer system. Structured analysis techniques were used for determining the information flow through the system. The system was then structured into modules using structured design and information hiding techniques. The detailed design of the system was described in pseudocode. The system was coded in assembler supplemented by a set of structured programming macros. A systematic bottom-up testing procedure was adopted for system integration.

DTL is an experimental programming language which has developed from an investigation of data structured design methods and data driven programming techniques. A DTL program is derived from a specification of the structure of its valid input and output languages. The program function is defined as a translation between these languages. A complex translation can be hierarchically structured into a network of simpler translations by stepwise refinement.

Structured design systems are systems in which the equations representing the equality and inequality constraints are sparse and highly precedenc orderable. An algorithm has been developed for such systems which is guaranteed, under certain assumptions, to arrive in a finite number of steps at a feasible point (that is, one which satisfies all the constraints) or to identify a subset of the constraints for which no feasible point can be found. The algorithm can be applied to a system with only inequality constraints or to a system with both equality and inequality constraints. The algorithm uses an indirect approach. It hypothesizes that a subset of constraints has no feasible region and then attempts to verify this conjecture. If successful, the subset is identified as infeasible and obviously no feasible point exists. If unsuccessful, either a new hypothesis can be generated or the algorithm has indirectly found a feasible point. Limited computational experience with the algorithm indicates that the number of steps required to find a feasible point for a system of constraints has been of the same order of magnitude as the total number of constraints in the system. For linear constraints, the efficiency of the algorithm has been comparable to phase one of the Simplex algorithm of Linear Programming.