leff@CSVAX.SEAS.SMU.EDU (Laurence Leff) (07/10/90)
Software Engineering Institute Information Management Annotated list of available documents for external distribution. Part I of VI 1 January 1986 - 29 June 1990 Technical reports that have DTIC numbers are available from the Defense Technical Information Center (DTIC) and the National Technical Information Service (NTIS). (As an example, ADA169705 is the DTIC number for the SEI report Toward a Reform of the Defense Department Software Acquisition Policy.) If you wish to request a copy of one of the following reports, please contact either DTIC or NTIS directly. DTIC: Defense Technical Information Center ATTN: FDRA Cameron Station Alexandria VA 22304-6145 NTIS: National Technical Information Service U.S. Department of Commerce Springfield, VA 22161 Technical Reports CMU/SEI-86-TR-1, ADA169705 Samuelson, P. Toward a Reform of the Defense Department Software Acquisition Policy A series of about 120 interviews were conducted with DoD personnel and others recommended by them. This report is an organized catalog of software acquisition problems reported, along with some assessments of their seriousness. CMU/SEI-86-TR-2, ADA182093 Samuelson, P. et al Proposal for a "New Rights in Software" Clause for Software Acquisitions by the Department of Defense This report recommends three distinct regulatory strategies for addressing difficulties the DoD has been experiencing with respect to legal issues related to software acquisitions. First, the report reiterates the Software Licensing Project's earlier recommendation that the DoD adopt the proposed Federal Acquisition Regulation (FAR) data rights provisions instead of the proposed revisions to the DoD supplement to the FAR (DoD FAR SUPP). Secondly, in the event that the DoD chooses to adopt a data rights procurement policy different from that found in the data rights provisions of the proposed FAR, this report recommends that the DoD adopt a separate "Rights in Software" clause for software acquisitions, rather than continuing the present practice of handling software procurements under the "Rights in Technical Data" clause. Reasons in support of a separate software acquisition policy, as well as a beginning model "Rights in Software" clause are offered. Finally, in the event that the DoD elects to retain the procurement format presently found in the DoD FAR SUPP provisions governing software and technical data acquisitions, this report offers several concrete recommendations for changes to those regulations which should result in a procurement policy which more effectively meets the mission needs of the Defense Department. CMU/SEI-86-TR-3, ADA178975 Barbacci, M. Durra: A Task-Level Description Language Preliminary Reference Manual Durra is a language designed to support the development of large-grained parallel programming applications. This document is a preliminary reference manual for the syntax and semantics of the language. CMU/SEI-86-TR-4, ADA178769 Barbacci, M. and Wing, J. Specifying Functional and Timing Behavior for Real-Time Applications We present a notation and a methodology for specifying the functional and timing behavior of real-time applications for a heterogeneous machine. In our methodology, we build upon well-defined, though isolated, pieces of previous work: Larch and Real-Time Logic. In our notation, we strive to keep separate the functional specification from the timing specification so that a task's functionality can be understood independent of its timing behavior. We show that while there is a clean separation of concerns between these two specifications, the semantics of both pieces as well as their combination are simple. CMU/SEI-86-TR-5, ADA200085 Harvey, H. Summary of the SEI Workshop on Software Configuration Management This report summarizes the discussion held during the Software Configuration Management meeting at the Software Engineering Institute in Pittsburgh on 16 July 1986. CMU/SEI-86-TR-6, ADA178771 Stockton, R. The Heterogeneous Machine Simulator The heterogeneous machine simulator is a program which attempts to simulate the proposed hardware for the heterogeneous machine at a high level, along with the low level programming abstractions which have been proposed. This will, hopefully, provide: 1) a reasonable basis for programmers to evaluate application designs in the absence of the actual machine; and 2) a testbed for designers to experiment with various reconfigurations which might be difficult to perform on the machine itself. This document presents a basic description of the system, and an example of how a simulation may be run. CMU/SEI-87-TR-1, ADA180905 Weiderman, N. et al Evaluation of Ada Environments The full report provides a detailed description of the methodology and examples of its usage. Chapter 1 gives an extended cross-environment analysis of the results of the project. For each of five experiment groups, it compares three APSEs. The chapter provides an overview of the results of all the experiments and is written for the technical manager. Chapter 2 describes in detail the methodology used for evaluating the environments, along with some of the background information and references to previous work in environment evaluation. Chapters 3 through 8 provide detailed descriptions of the six experiment groups. Here one can find the information on particular criteria, questions, and life cycle activities that were tested for each experiment, as well as test scripts, checklists, and resulting data that were collected. CMU/SEI-87-TR-2, ADA178971 Martin, A. and Deasy, K. The Effect of Software Support Needs on DoD Software Acquisition Policy: Part 1: A Framework for Analyzing Legal Issues This report summarizes the significant technical and managerial considerations that affect the maintenance and enhancement of software. Prior work suggested that it is often in the acquisition of intellectual property needed to maintain and enhance software that data rights disputes arise between DoD and the private sector. For this reason, an understanding of DoD's maintenance and enhancement requirements is a necessary predicate toward shaping a data rights/software acquisition policy that achieves the proper balance between the intellectual property needs of DoD and the proprietary interests of private industry. A survey of software engineering literature revealed no study that addressed this important subject. Accordingly, the Software Licensing Project undertook to examine the issue itself. Although this report discusses technical and managerial issues, it is principally intended as a guide for lawyers and policymakers who deal with, and have regulatory responsibility for, software and data rights acquisition issues. CMU/SEI-87-TR-4, ADA182982 Druffel, L. et al Software and System Warranty Issues This report addresses technical and administrative issues associated with the system warranty process, and recommends a straightforward, two-page generic system warranty clause that covers software, not in isolation, but as part of a warranted system. The report describes one approach to relieving problems of system failure, and addresses legal, technical, and administrative issues that support warranty enforcement. The goal is to ease the government's burden of proving the existence of a defect for which the warranty clause provides a remedy. The key to satisfying that goal is to develop technical tests and specifications that provide objective and demonstrable standards against which a claim for breach of warranty can be measured. CMU/SEI-87-TR-5, ADA181853 Cooper, E. Distributed Systems Technology Survey This report is one of a series of survey reports. It is not intended to provide an exhaustive discussion of topics pertinent to the area of distributed systems technology. Rather, it is intended as an informative review of the technology surveyed. These surveys were conducted in late 1985 and early 1986. One of the core technology areas in which project members were interested is distributed systems technology. This report surveys the technical issues involved in designing distributed systems, with particular emphasis on those aspects that affect software engineering environments. CMU/SEI-87-TR-6, ADA181852 Feiler, P. User Interface Technology Survey This report is one of a series of survey reports. It is not intended to provide an exhaustive discussion of topics pertinent to the area of distributed systems technology. Rather, it is intended as an informative review of the technology surveyed. These surveys were conducted in late 1985 and early 1986. One of the core technology areas in which project members conducted a survey was user interface technology. This report attempts to do two things: specify an understanding of user interfaces by presenting a taxonomy that encompasses the various aspects of user interfaces, and indicate the state of the technology today by highlighting some of the major issues. CMU/SEI-87-TR-7, ADA181156 Newcomer, J. Tool Interface Technology This report is one of a series of survey reports. It is not intended to provide an exhaustive discussion of topics pertinent to the area of user interface technology. Rather, it is intended as an informative review of the technology surveyed. These surveys were conducted in late 1985 and early 1986. CMU/SEI-87-TR-8, ADA182003 Ford, G. et al Software Engineering Education: An Interim Report from the Software Engineering Institute The goals and activities of the Software Engineering Institute's Education Program are described. Two curriculum recommendations are presented, one for a professional Master of Software Engineering degree program, and the other for an undergraduate project course in software engineering. Also presented is an organizational structure for software engineering curriculum content. CMU/SEI-87-TR-9, ADA182023 Foreman, J. and Goodenough, J. Ada Adoption Handbook The Ada Adoption Handbook provides program managers with information about how best to tap Ada's strengths and manage this new software technology. Although the issues are complex, they are not all unique to Ada. Indeed, many of these issues must be addressed when using any language for building sophisticated systems. The handbook addresses the advantages and risks inherent in adopting Ada. Significant emphasis has been placed on providing information and suggesting methods that will help program and project managers succeed in adopting Ada across a broad range of application domains. The handbook focuses on the following topics: program management issues including costs and technical and program control; Ada's goals and benefits; software tools with emphasis on compiler validation and quality issues; the state of Ada technology as it relates to system engineering; the application of special purpose languages; issues related to mixing Ada with other languages; possible productivity benefits resulting from software reuse; and implications for education and training. CMU/SEI-87-TR-10 Firth, R. et al A Guide to the Classification and Assessment of Software Engineering Tools Software engineering tools are computer programs that assist people in doing the work of software engineering. As understanding of the software engineering process has broadened and the need to solve problems has intensified, there has been increasing interest in using software engineering tools. Understanding what a tool does and comparing it to similar tools are difficult tasks given the diversity of functionality that exists. This report describes a tool classification technique that helps those investigating tools decide where a tool fits in the software engineering process and identify what a tool does or doesn't do. It also provides guidance to the tool evaluation process and lists specific criteria that should be considered when evaluating tools. CMU/SEI-87-TR-11, ADA182895 Humphrey, W. Characterizing the Software Process: A Maturity Framework Improvement in the performance of software development organizations is an essential national need. The improvement process has five basic elements: 1. an understanding of the current status of the development process, 2. a vision of the desired process, 3. a prioritized list of required improvement actions, 4. a plan to accomplish these actions, and 5. the resources and commitment to execute the plan. This paper addresses the first three of these elements by providing a model for software organizational improvement. The structure of this model provides five maturity levels, identifies the key improvements required at each level, and establishes a priority order for implementation. This model has been tested with a number of organizations and found to reasonably represent the status and needs of actual software development groups. CMU/SEI-87-TR-12 Hansen, G. et al The Analysis of the Technical Order Production Process at Ogden Air Logistics Center and Recommendations for the Improvement of the Process This report details the process used by Ogden Air Logistics Center to maintain Operational Flight Program Technical Orders for the F-16 airplane. It is of general interest because it makes recommendations for the improvement of the process and also recommendations for technology insertion. Since the Technical Order modification process is not entirely different from documentation maintenance activities in industry, this report is widely applicable. CMU/SEI-87-TR-13, ADA185742 Martin, A. and Deasy, K. Seeking the Balance Between Government and Industry Interests in Software Acquisition. Volume I. A Basis for Reconciling DoD and Industry Needs for Rights in Software The policy under which the Department of Defense (DoD) acquires rights in software and technical data has, in the past, been imbalanced in the direction of obtaining more rights than necessary to meet its needs. As noted by the Packard Commission, a more balanced policy is in the interests of both the DoD and industry. The DoD has recently adopted a new policy for acquiring rights in technical data, and is developing a separate policy for acquiring rights in software. This report offers several recommendations for achieving a balanced policy as to government funded software, privately funded software, and mixed funding software that will meet the mission needs of the DoD while enabling contractors to protect their proprietary interests, and commercialize their software products. CMU/SEI-87-TR-14, ADA200601 Meyers, C., and Cappellini, A. The Use of Representation Clauses and Implementation-Dependent Features in Ada: I. Overview This report, the first in a series, presents an overview of the aspects of the Ada language relating to representation clauses and implementation-depen dent features. Particular emphasis is given to the use of Ada for application to packed data structures. This report is in part tutorial, and several examples from real-time, mission-critical systems are discussed in detail. A brief discussion of design guidelines for the use of representation clauses and implementation-dependent features is included. CMU/SEI-87-TR-15, ADA188925 Meyers, C. and Cappellini, A. The Use of Representation Clauses and Implementation-Dependent Features in Ada: IIA. Evaluation Questions This report is the second in a series on the use of representation clauses and implementation-dependent features in Ada. It is the purpose of this document to specify a set of questions relevant to the assessment of the support of representation clauses and implementation-dependent features provided by an Ada compiler. The questions identified are categorized according to functionality and address both qualitative and quantitative aspects. CMU/SEI-87-TR-16, ADA183429 Humphrey, W. and Kitson, D. Preliminary Report on Conducting SEI-Assisted Assessments of Software Engineering Characterizing the state of software engineering practice within an organization is a necessary prerequisite to orderly, meaningful, and sustainable improvement of the organizations ability to produce or support cost-effective, high quality software products. The Software Engineering Institute is developing a methodology for conducting SEI-assisted assessments of software engineering capability. The assessment methodology has five phases: 1. selecting the candidate organization, 2. preparing for the assessment, 3. conducting the assessment, 4. communicating final assessment findings and action recommendations, and 5. post-assessment follow-up activities. This report describes the methodology in detail. CMU/SEI-87-TR-17, ADA188926 Meyers, C. and Cappellini, A. The Use of Representation Clauses and Implementation-Dependent Features in Ada: IIIA. Qualitative Results for VAX Ada This report, one in a series, provides a qualitative assessment of the support of representation clauses and implementation-dependent features in Ada provided by the VAX Ada compiler, Version 1.3. The evaluation questions that were presented in a previous report of this series form the basis of the qualitative assessment. A subjective evaluation of the support provided for these features is also presented. CMU/SEI-87-TR-18, ADA200602 Meyers, C. and Cappellini, A. The Use of Representation Clauses and Implementation-Dependent Features in Ada: IIB. Experimental Procedures This report is one in a series dealing with the use of representation clauses and implementation-dependent features in Ada. The purpose of this report is to discuss detailed experimental procedures to assess compiler support. It is readily acknowledged that the domain of possible experimentation is large. To facilitate the experimentation, a methodology is proposed that relies on program generators and automated analysis tools. An example of the methodology is presented in some detail. CMU/SEI-87-TR-19 Meyers, C. and Cappellini, A. The Use of Representation Clauses and Implementation-Dependent Features in Ada: IVA. Qualitative Results for Ada/M(44) This report, one in a series, provides a qualitative assessment of the support of representation clauses and implementation-dependent features in Ada provided by the Ada/M(44) compiler, Version 1.6. The evaluation questions that were presented in a previous report of this series form the basis of the qualitative assessment. A subjective evaluation of the support provided for these features is also presented. CMU/SEI-87-TR-20, ADA200603 Tomayko, J. Teaching a Project Intensive Introduction to Software Engineering This report is meant as a guide to the teacher of the introductory course in software engineering. It contains a case study of a course based on a large project. Other models of course organization are also discussed. Additional materials used in teaching the course and samples of student-produced documentation are also available. CMU/SEI-87-TR-21, ADA185697 Altman, N. and Weiderman, N. Timing Variation in Dual Loop Benchmarks Benchmarks that measure time values using a standard system clock often employ a dual loop design. One of the important assumptions of this design is that textually identical loop statements will take the same amount of time to execute. This assumption was tested on two bare computers with Ada test programs and has been demonstrated to be inaccurate in these specific test cases. CMU/SEI-87-TR-22, ADA187231 Altman, N. Factors Causing Unexpected Variations in Ada Benchmarks Benchmarks are often used to describe the performance of computer systems. This report considers factors that may cause Ada benchmarks to produce inaccurate results. Included are examples from the ongoing benchmarking efforts of the Ada Embedded Systems Testbed (AEST) Project using bare target computers with several Ada compilers. CMU/SEI-87-TR-23, ADA187230 Humphrey, W. and Sweet, W. A Method for Assessing the Software Engineering Capability of Contractors This document provides guidelines and procedures for assessing the ability of potential DoD contractors to develop software in accordance with modern software engineering methods. It includes specific questions and a method for evaluating the results. CMU/SEI-87-TR-24, ADA200542 Dart, S. et al Software Development Environments "Environment" refers to the collection of hardware and software tools that a system developer uses to build software systems. As technology improves and user expectations grow, an environment's functionality tends to change. Over the last 20 years, the set of software tools available to developers has expanded considerably. We can illustrate this change by observing some distinctions in the terminology. "Programming environment" and "software development environment" are often used synonymously, but here we make a distinction between the two. CMU/SEI-87-TR-25, ADA200611 Klein, D. and Firth, R. Final Evaluation of MIPS M/500 Final Report for the RISC Insertion Project In response to a request from the DoD, an analysis of a Reduced Instruction Set Computer (RISC) processor, the MIPS M/500, was performed. All aspects of processor capabilities and support software were evaluated, tested, and compared to familiar Complex Instruction Set Computer (CISC) architectures. In all cases, the RISC computer and its support software performed better than a comparable CISC computer. This report provides the general and specific results of these analyses, along with the recommendation that the DoD and other government agencies seriously consider this or other RISC architectures as a highly viable and attractive alternative to the more familiar but less efficient CISC architectures. CMU/SEI-87-TR-26, ADA191096 Weiderman, N. et al Ada for Embedded Systems: Issues and Questions This report addresses issues and questions related to the use of Ada for embedded systems applications; it contains some preliminary recommendations for compilation system implementors, application developers, program managers, and Ada policy makers. The issues and questions provide the context for the Real-Time Embedded Systems Testbed (REST) Project at the SEI, where staff members are investigating software development and performance issues for real-time embedded systems. CMU/SEI-87-TR-27, ADA200607 Donohoe, P. Ada Performance Benchmarks on the MicroVAX II: Summary and Results This report documents the results obtained from running the University of Michigan and the SIGAda Performance Issues Working Group (PIWG) Ada performance benchmarks on a DEC VAXELN MicroVAX II using the DEC VAXELN Ada compiler. A brief description of the benchmarks and the test environment is followed by a discussion of some problems encountered and lessons learned. The output of each benchmark program is also included. CMU/SEI-87-TR-28, ADA200608 Donohoe, P. A Survey of Real-Time Performance Benchmarks for the Ada Programming Language This survey provides a summary description of some of the major Ada benchmarks currently available and an evaluation of their applicability to the Real-Time Embedded Systems Testbed Project at the SEI. The benchmarks discussed are the University of Michigan benchmarks, the ACM Performance Issues Working Group (PIWG) benchmarks, and the prototype Ada Compiler Evaluation Capability (ACEC) of the Institute for Defense Analyses (IDA). CMU/SEI-87-TR-29, ADA188100 Borger, M. VAXELN Experimentation: Programming a Real-Time Clock and Interrupt Handling Using VAXELN Ada 1.1 This report describes the results of implementing an interrupt handler totally in Ada for a MicroVAX II/VAXELN 2.3 target system, the VAXELN 1.1 Ada compiler, and a KWV11-C programmable real-time clock. It provides an overview of VAXELN interrupt handlers and the operation of the real-time clock; discusses and demonstrates the use of VAXELN kernel services to establish a link between the clock's interrupt and the starting address of an interrupt service routine; presents an Ada package of interfaces to the KWV11-C device; provides Ada source code examples demonstrating the use of this package; and presents relevant observations, recommendations, and measurement results. CMU/SEI-87-TR-30, ADA188932 Weiderman, N. Criteria for Constructing and Using an Ada Embedded System Testbed The purpose of this report is to list some of the criteria used in five aspects of the project: the hardware configuration, the software configuration, the real-time application, the Ada real-time experiments, and the benchmarking and instrumentation techniques. Each criterion will include a rationale. Each of the criteria listed in this report will be categorized as either essential, highly desirable, or desirable. CMU/SEI-87-TR-31, ADA200609 Weiderman, N., et al. Annual Technical Report for Ada Embedded Systems Testbed Project The purpose of the Ada Embedded Systems Testbed Project (now called the Real-Time Embedded Systems Project) is to investigate some of the critical issues in using Ada for real-time embedded applications, particularly the extent and quality of the runtime support facility provided by Ada implementations. The project's objective has been to generate new information about using Ada in real-time embedded systems. This information is in the form of benchmark test results, higher level experiment results, and lessons learned in designing and implementing real-time applications in Ada. This technical report provides an overview of the results produced in the first year of the project (through September 30, 1987). Details of these results are contained in other referenced technical reports. CMU/SEI-87-TR-32, ADA200612 Borger, M. VAXELN Experimentation: Programming a Real-Time Periodic Task Dispatcher Using VAXELN Ada 1.1 The purpose of this paper is to provide the reader with some technical information and observations, Ada source code, and measurement results based on experimentation with respect to developing a real-time periodic task dispatcher in Ada. In this context, a periodically scheduled task set implies that each task in the set is executed at its own fixed frequency; a periodic task dispatcher is a software component that schedules the individual tasks at their implied runtime frequency. The results presented here are specific to a MicroVAX-II/VAXELN 2.3 target system, the VAXELN 1.1 Ada compiler, and a KWV11-C programmable real-time clock. Specifically, these results provide answers to the question: How can one achieve the effect of scheduling a set of periodic Ada tasks when the runtime frequency of some of the individual tasks is less than the clock-cycle frequency supported by an Ada runtime implementation? CMU/SEI-87-TR-33, ADA200604 Landherr, S. and Klein, M. Inertial Navigation System Simulator: Behavioral Specification The Real-Time Embedded Systems Testbed Project at the SEI is specifying and developing a representative real-time application. This document augments an original set of specifications written by a Navy affiliate. The purpose of this behavioral specification is to clarify and augment the original. CMU/SEI-87-TR-34, ADA200605 Klein, M. and Landherr, S. Inertial Navigation System Simulator Program: Top-Level Design A real-time Ada application, an Inertial Navigation System (INS) simulator, is being developed by the Real-Time Embedded Systems Testbed Project as a vehicle to analyze issues regarding the use of Ada in the real-time embedded domain and to provide a context for future experimentation. The technical philosophy behind developing a real-time Ada artifact is to: (1) select a representative (e.g., strict timing demands, multiple concurrent activities, low-level I/O, error handling, interrupts, and periodic activities) real-time application; (2) use Ada tasks as the unit of concurrency for the real-time design; and (3) apply any relevant practical results being produced by the real-time scheduling research community. In particular, the INS simulator must satisfy a set of timing requirements that are similar to an INS with respect to data updating, message transmission, and message reception. This document discusses the top-level design of this application from three points of view: data flow perspective, concurrency and control perspective, and the Ada module perspective. CMU/SEI-87-TR-35, ADA188928 Van Scoy, R. Prototype Real-Time Monitor: Executive Summary This report summarizes the history, goals, and conclusions of the prototype real-time monitor development effort. This effort was undertaken to address two specific technical questions: 1) How can user tools find, access, and display data hidden in the bodies of Ada applications? 2) How can user tools be layered on top of Ada applications? The effort resulted in a generally usable prototype, which is documented by four other SEI reports (CMU/SEI-87-TR-36 through CMU/SEI-87-TR-39). CMU/SEI-87-TR-36, ADA188929 D'Ippolito, R. et al Prototype Real-Time Monitor: Requirements The requirements imposed by flight simulators and good software engineering practice on Ada systems force software engineers to seek new solutions to the problem of monitoring executing software. This report examines some of these requirements and, based on these requirements, defines a subset for implementation as a prototype real-time monitor (RTM). CMU/SEI-87-TR-37, ADA188930 Van Scoy, R. et al Prototype Real-Time Monitor: User's Manual This report defines the user interface to the prototype real-time monitor (RTM). It defines the concepts and commands needed by a software engineer to use the RTM. In addition to defining the user interface, the report explains the steps needed to tailor the RTM to work with the user's application. CMU/SEI-87-TR-38, ADA188931 Van Scoy, R. et al Prototype Real-Time Monitor: Design This report describes the software design used to implement the prototype real-time monitor requirements. The design is presented at three levels: system level, object level, and package architecture level. The report concludes with a discussion of the key implementation obstacles that had to be overcome to develop a working prototype: determining system addresses, communicating with an executing application, accessing application memory, converting data into human-readable form, and distributed CPU architectures. CMU/SEI-87-TR-39, ADA191095 Van Scoy, R. Prototype Real-Time Monitor: Ada Code This report documents the Ada code of the prototype real-time monitor (RTM). CMU/SEI-87-TR-40, ADA200610 Donohoe, P. Ada Performance Benchmarks on the Motorola MC68020: Summary and Results This report documents the results obtained from running the ACM SIGAda Performance Issues Working Group (PIWG) and the University of Michigan Ada performance benchmarks on a Motorola MC68020 microprocessor (MVME133 VMEmodule Monoboard Microcomputer), using the Systems Designers Ada-Plus, the TeleSoft TeleGen2, and the Verdix VAX/VMS hosted cross-compilers. A brief description of the benchmarks and the test environment is followed by a discussion of some problems encountered and lessons learned. Wherever possible, the output of each benchmark program is also included. CMU/SEI-87-TR-41, ADA200606 Firth, R. et al A Classification Scheme for Software Development Methods Software development methods are used to assist with the process of designing software for real-time systems. Many such methods have come into practice over the last decade, and new methods are emerging. These new methods are more powerful than the old ones, especially with regard to real-time aspects of the software. This report describes a classification scheme for software development methods, includes descriptions of the major characteristics of such methods, and contains some words of advice on choosing and applying such methods. CMU/SEI-87-TR-42, ADA199877 Hefley, B. Issues in Software: A Blue Two Visit Feasibility Assessment The SEI participated in a series of fact-finding meetings sponsored by the Air Force Coordinating Office for Logistics Research to gather information necessary to set the scope for and to implement one or more Blue Two Visits on software. The purpose of a Blue Two Visit (BTV) is to introduce to industry's top design engineers and program managers the day-to-day constraints Air Force maintainers face on front-line operations bases. The participants experience first-hand the effects of design on maintenance. This exposure has been significant in bridging the gap between DoD and industry in understanding, documenting, and supporting Air Force weapon system requirements to increase combat supportability. This report documents discussions that attempt to address the following questions for a software-oriented BTV: 1) Do software maintainers and users have messages for software designers and programmers? 2) What are these messages? 3) How can these messages be best communicated? 4) To whom should these messages be targeted? 5) What should the BTV be called? CMU/SEI-87-TR-43, ADA191097 Lee, K. et al An OOD Paradigm for Flight Simulators This report presents a paradigm for object-oriented implementations of flight simulators. It is a result of work on the Ada Simulator Validation Program (ASVP) carried out by members of the technical staff at the SEI. CMU/SEI-87-TR-44, ADA188927 Ford, G. editor Report on the SEI Workshop on Ada in Freshman Courses The Undergraduate Software Engineering Education Project of the SEI Education Program sponsored a workshop on Ada in Freshman Courses in June 1987. The workshop brought together several educators to discuss how the software engineering content of beginning programming and data structures courses might be improved. This report describes the workshop and summarizes the discussions and conclusions, and it also includes the position papers prepared by the participants. CMU/SEI-87-TR-45, ADA188923 Nestor, J. Views for Evolution in Programming Environments Programming environments have become a focal point for much of the work directed toward improving the practice of software engineering. Such environments must provide mechanisms for recording and organizing the complex set of persistent technical and management data associated with all parts of the life cycle of large software systems. This paper focuses on one important aspect of such persistent data: how to allow evolution when the existing information must be preserved without change to maintain history. First, the role of history in programming environments is discussed. Next, the additional demands of evolution are considered and shown to lead to a set of problems. View mechanisms are suggested as a solution to the problems. A simple example involving file system directory structure is presented to illustrate these problems. A simple view mechanism, called multidirectories, is introduced and shown to solve the illustrated problems. CMU/SEI-87-TR-46, ADA188924 Nestor, J. Evolving Persistent Objects in a Distributed Environment This paper considers a class of objects, called incrementally mutable objects, that are intermediate between mutable and immutable objects. Intuitively, the only permitted modifications to an incrementally mutable object are those that add new information to the object while preserving existing information. Changes to incrementally mutable objects do not require central synchronization. When a network becomes partitioned, the same incrementally mutable object can be safely modified in each subnetwork. A mutable object can be modeled by a set of immutable objects that represent each value of the object over time and an incrementally mutable object that relates each immutable object to its successor. Multiple successors are permitted to represent parallel changes. CMU/SEI-87-TR-47, ADA188922 Stone, D. and Nestor, J. IDL: Background and Status This paper presents an overview of the Interface Description Language (IDL). We describe the language and its history. We also discuss the status of the IDL community. CMU/SEI-87-TR-48, ADA199634 Engle, C. et al Interfacing Ada and SQL The SEI was asked by the Ada Joint Program Office to investigate the problem of interfacing programs written in Ada with database management systems implementing the SQL database language. The authors decided to concentrate on a description of the problems involved in producing an interface that would be worthy of becoming a standard. This document is meant to assist the reader in answering the question "What constitutes a good interface between Ada and SQL?" The document should be useful both in the production of a standard and in the analysis of any proposed standard. --