1、 Guide Managing the Use of Commercial Off the Shelf (COTS) Software Components for Mission-Critical Systems AIAA G-118-2006 AIAA standards are copyrighted by the American Institute of Aeronautics and Astronautics (AIAA), 1801 Alexander Bell Drive, Reston, VA 20191-4344 USA. All rights reserved. AIAA
2、 grants you a license as follows: The right to download an electronic file of this AIAA standard for temporary storage on one computer for purposes of viewing, and/or printing one copy of the AIAA standard for individual use. Neither the electronic file nor the hard copy print may be reproduced in a
3、ny way. In addition, the electronic file may not be distributed elsewhere over computer networks or otherwise. The hard copy print may only be distributed to other employees for their internal use within your organization. AIAA G-118-2006 Guide Managing the Use of Commercial Off the Shelf (COTS) Sof
4、tware Components for Mission-Critical Systems Sponsored by American Institute of Aeronautics and Astronautics Approved 13 October 2006 Abstract The purpose of this Guide is to assist development and maintenance projects (teams and individuals) that have to address the use of, or consideration of, CO
5、TS products within large, complex systems, including but not limited to mission critical systems. This assistance is provided by capturing a set of information about COTS products (benefits, risks, recommended practices, lifecycle activity impacts) and mission critical systems (variety of MCS, speci
6、al needs for MCS, differences between MCS and other types of systems) and then providing some linkage between these topics so that various types of stakeholders can find useful information. The document should be of value to both management and technical individuals/teams. It should also be of value
7、 to teams that are dealing with non-MCS, in that the scope is not limited to only MCS. AIAA G-118-2006 ii Managing the use of commercial off the shelf (COTS) software components for mission-critical systems : AIAA G-118-2006 guide. p. cm. Includes bibliographical references. ISBN 1-56347-915-X (prin
8、t) - ISBN 1-56347-916-8 (electronic) 1. Aeronautics-Computer programs. 2. Astronautics-Computer programs. 3. Astronautics-United States-Equipment and supplies. 4. Software engineering. 5. Commercial products. I. American Institute of Aeronautics and Astronautics. TL563.M36 2006 629.102855-dc22 20060
9、39308 Published by American Institute of Aeronautics and Astronautics 1801 Alexander Bell Drive, Reston, VA 20191 Copyright 2006 American Institute of Aeronautics and Astronautics All rights reserved No part of this publication may be reproduced in any form, in an electronic retrieval system or othe
10、rwise, without prior written permission of the publisher. Printed in the United States of America AIAA G-118-2006 iii Contents Forewordvi Introduction viii 1 Scope 1 2 Applicable Documents . 1 3 Vocabulary 1 3.1 Acronyms and Abbreviated Terms 1 3.2 Terms and Definitions 2 4 Document Roadmap 2 5 The
11、COTS Decision: Background and Overview . 4 5.1 Why COTS? 4 5.2 Mission Critical Systems and Requirements 5 5.2.1 Characteristics of Mission Critical Systems (MCS) 5 5.2.2 Mission Critical System Requirements 6 6 COTS Software Benefits and Risks 7 6.1 COTS Benefits 7 6.2 COTS Risks 8 6.2.1 Incorrect
12、Make Versus Buy Trade Studies 8 6.2.2 System incompatibilities. 8 6.2.3 Human/Machine Interfaces and Operational Procedures 8 6.2.4 Underestimated Total Program Costs. 9 6.2.5 Impacts to Lifecycle Model Activities. 9 6.2.6 Product Volatility. 9 6.2.7 Vendor Viability. 9 6.2.8 Product Support 9 6.2.9
13、 Likelihood of Wrappers. 9 6.2.10 Product Testing/Evaluation 10 6.2.11 Multiple COTS Product Integration 10 6.2.12 Problem Resolution 10 6.2.13 Product Knowledge/Training 10 6.2.14 Product Version Control/CM 10 6.2.15 Product and Process Insights 10 6.2.16 Dormant Code 11 7 Recommended Practices. 11
14、 7.1 Effective Trade Studies 13 7.1.1 The Make Versus Buy Decision. 13 AIAA G-118-2006 iv 7.1.2 Product Selection/Evaluation. 13 7.2 Insights 14 7.2.1 Insights Into the COTS Products. 14 7.2.2 Insights Into the COTS Vendors Development/Maintenance Processes. 14 7.2.3 Insight Into the COTS Vendors Bu
15、siness Viability. 14 7.2.4 Insight Into the COTS Marketplace . 15 7.3 Early and Ongoing Testing and Prototyping. 15 7.4 Assessing Impacts of “Wrapper” Software . 16 7.5 Problem Resolution 16 7.6 Product Knowledge Acquisition. 16 7.7 Product Support 17 7.8 Configuration Management and Version Control
16、 . 17 7.9 Cost Estimation Effectiveness. 17 8 COTS Activities Throughout the Life Cycle. 17 8.1 Mapping COTS Software Activities to the Primary Life Cycle Development Process 18 8.2 The COTS Software Life Cycle 19 8.2.1 COTS Life Cycle Partitions 19 8.2.2 COTS Software Activities. 19 8.3 Mapping Ris
17、ks to COTS Software Activities. 20 8.4 COTS Specific Activities within each Partition of the Software Life Cycle 24 8.4.1 Product Feasibility 24 8.4.2 Product Evaluation and Selection 26 8.4.3 Testing, Integration, Acquisition and Maintenance. 27 9 COTS Software Activities in the Context of Software
18、 Life Cycle Processes. 28 9.1 Summary of Process Activity Modifications 28 9.2 Primary Life Cycle Process Modifications. 32 9.2.1 Acquisition Process Modifications. 32 9.2.2 Supply Process Modifications (Contract) 33 9.2.3 Development Process Modifications . 33 9.2.4 Operation Process Modifications.
19、 48 9.2.5 Maintenance Process Modifications 48 9.3 Supporting Process Modifications . 48 9.3.1 Documentation . 48 9.3.2 CM. 49 9.3.3 Problem resolution . 50 10 Examples, Case Studies 50 AIAA G-118-2006 v 10.1 COTS Certification Plan Example . 50 10.2 COTS in Enterprise Wide Financial Management Syst
20、em 50 11 Summary and conclusions. 51 12 Bibliography 51 Figures Figure 1 G-118 Roadmap 3 Figure 2 Synchronization of COTS Software Activities and the Software Life Cycle Development Process 18 Figure 3 Example Custom-Built Software-Centric Waterfall Life Cycle Model 34 Figure 4 Example COTS Software
21、-Centric Waterfall Life Cycle Model. 35 Tables Table 1 G-118 User Perspectives . 4 Table 2 Mission Critical versus Non-Mission Critical System Characteristics 5 Table 3 Criticality Level Mappings. 6 Table 4 Applicable Mitigation Strategies for Risks . 11 Table 5 Life Cycle Partitions 19 Table 6 COTS
22、 Software Activities . 20 Table 7 COTS Activity Related Risks for Product Feasibility Partition 21 Table 8 COTS Activity Related Risks for Product Evaluation and Selection Partition 22 Table 9 COTS Activity Related Risks for Testing and Maintenance Partition. 23 Table 9 COTS Activity Related Risks f
23、or Testing and Maintenance Partition (continued). 24 Table 10 Summary of Acquisition Process Modifications for COTS 29 Table 11 Summary of Supply Process Modifications for COTS 29 Table 12 Summary of Development Process Modifications for COTS 30 Table 13 Summary of Operation Process Modifications fo
24、r COTS . 31 Table 14 Summary of Maintenance Process Modifications for COTS 31 Table 15 Summary of CM Process Modifications for COTS 32 Table 16 Summary of Problem resolution Process Modifications for COTS 32 Table 17 Summary of Training Process Modifications for COTS 32 Table 18 Examples of COTS Eff
25、ects on System Requirements 37 Table 19 Examples of COTS Effects on Software Requirements . 41 Table 20 Potential Software Requirements for Particular Types of COTS Software 43 AIAA G-118-2006 vi Foreword Commercial off-the-shelf (COTS) products are being considered for inclusion in ever more comple
26、x and critical systems. There are clear advantages to considering the use of COTS in such complex or critical systems but given the rigorous needs of such critical systems or subsystems, there have begun to emerge concerns about the suitability of COTS for such applications. This guide identifies so
27、me of the characteristics of mission critical systems (MCS) that make the selection process of COTS products (hardware, software, subsystems, etc., but especially software) an emerging success factor in total system acceptance. Mission critical system characteristics such as reliability, safety, ava
28、ilability, maintainability and certification tend to influence whether or not COTS should be considered for a given application. Once the suitability of COTS has been determined it may be possible to place additional requirements on the product and/or the products vendor for such mission critical ap
29、plications. Further, it is possible that certain system requirements and expectations may need to be modified because of the inclusion of COTS products into that system. As COTS products continue to be considered as candidates for inclusion within MCS, there are likely to be additional concerns and
30、factors to emerge that will influence how both buyers and vendors decide if and/or when to use COTS products. The benefits and risks of using COTS in MCS are detailed in this guide. Risk mitigation approaches applicable to the selection and usage of COTS software components in MCS are discussed as t
31、hey apply to the software product lifecycle. This guide was initially focused on the use of COTS software products in MCS. As it was developed, it quickly became clear that some/much of what was being captured applied to COTS products other than just software. It also became evident to the committee
32、 that much of what was being captured applied to non-MCS. This guide will be most useful and applicable to large, complex systems that are considering or actually using COTS software products. The user is also likely to find this guide of value in COTS hardware projects as well as to systems that ra
33、nge from spacecraft and aerospace applications to human resource or financial applications. In addition, this guide can apply to test hardware and software. This Guide was produced under the auspices of the Software Systems Technical Committee (SSTC) of the American Institute of Aeronautics and Astr
34、onautics (AIAA). It was initially conceived by Ronald J. Kohl, of R. J. Kohl selecting which ones to use; and integrating their use effectively with the overall system development, operation, and maintenance processes. This document is organized to provide easy access to information relevant to thos
35、e decisions. AIAA G-118-2006 3 Figure 1 G-118 Roadmap This document is organized as follows: Sections 1-4 introduce the document, explain its scope, and help readers identify sections of interest. Section 5 provides a context for the COTS decisions. It contains a discussion about the differences in
36、custom built software and COTS software products and attempts to identify a few key factors that contribute to the different risks associated with COTS products as well as the reasons for changes in lifecycle activities. Section 6 presents an overview of the benefits and risks associated with using
37、COTS software components. Section 7 identifies a set of Recommended Practices which are intended to improve the existing set of technical processes for a COTS-based systems project and which can be used to mitigate the risks described in section 6. Section 8 defines the major COTS-specific activitie
38、s needed in the life cycle, such as product evaluation and selection, which do not usually occur for custom-built software. Section 9 places the activities in section 8 into the context of a standard (IEEE/EIA 12207) set of software life cycle processes. For each process in the standard it details o
39、ther minor modifications, which are necessary to incorporate COTS software components. Section 10 collects illustrations, examples and case studies of process execution, lessons learned, or other experiences with COTS software components. Contents of this section are contributed by users so that oth
40、ers may benefit from their experiences. Section 11 summarizes the document and presents future work planned for later revisions as well as places where user feedback is requested. Section 12 contains an extensive bibliography on COTS software-related topics, organized by topic. AIAA G-118-2006 4 In
41、a process standard describing considerations for using COTS software there are various perspectives of the decision that must be incorporated to be meaningful. This guide considers a variety of user perspectives. These include users new to COTS software products, novice integrators, managers, as wel
42、l as experienced users accustomed to formal lifecycle integration. This guide has been designed to address some of the needs, though not in exhaustive detail, of the different user types. Table 1 provides a general road map for users with respect to this guidebook. Users with specific interest will
43、be directed to “Suggested parts of the Guide” for appropriate usage of its components. The suggested parts in Table 1 that are described in bold font are considered to be the primary focus for the particular user. The suggested sections without bold font are considered references that provide suppor
44、ting information to the primary focus. Readers generally familiar with the use of COTS software components, but desiring more in-depth information on a particular topic may find the detailed bibliography most helpful. Table 1 G-118 User Perspectives Class of User Perspective and Interests Suggested
45、parts of Guide New to COTS Software Inexperienced with COTS software but curious about the COTS software decision and the pros and cons of COTS software products 5, 6 Novice Integrators Inexperienced with COTS software but need to integrate COTS software into their systems 5, 6, 7, 8, 10 Managers Sp
46、onsors that need an overall view of the COTS software decision and risks within the general lifecycle 5, 6, 8, 10 Experienced the relative weighting to the importance of each; the need for control of future system evolutionary changes versus the dependency on COTS vendors to provide future product c
47、hanges; the need for stability and reliability across the system versus the volatility inherent in COTS products; test and integration needs versus COTS test benches; extra software features versus custom crafted. 7.1.2 Product Selection/Evaluation Trade studies are critical to successfully selectin
48、g one (or a few) COTS product(s) from a large collection of candidate COTS products. The key to success of such product selection/evaluation trade studies is to establish the right set of criteria very early in the lifecycle. The types of criteria that should be considered are identified below. It s
49、hould be noted that there are frequently additional criteria that are dependent on the domain of application, the acquisition approach, the nature of funding support, etc., that are not listed below but for which the trade study team should be accounting. Match between product features and system needs/requirements Viability/stability of the vendor AIAA G-118-2006 14 Ease of product integration (e.g. complies with interface standards) Ability to acquire mission support and maintenanc
