1、 DIRECTIVE NO. GPR 7123.1 APPROVED BY Signature: Original signed by EFFECTIVE DATE: October 1, 2008 NAME: Robert D. Strain EXPIRATION DATE: October 1, 2013 TITLE: Director CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THIS IS THE CORRECT VERS
2、ION PRIOR TO USE. GSFC 3-17 (10/04) Goddard Procedural Requirements (GPR)COMPLIANCE IS MANDATORYResponsible Office: 599/Mission Systems Engineering Branch Title: Systems Engineering TABLE OF CONTENTS PREFACE P.1 PURPOSE P.2 APPLICABILITY P.3 AUTHORITY P.4 REFERENCES P.5 CANCELLATION P.6 SAFETY P.7 T
3、RAINING P.8 RECORDS P.9 METRICS P.10 DEFINITIONS PROCEDURES 1. Roles and Responsibilities 2. The Systems Engineering Life Cycle 3. Communications 4. Key Systems Engineering Functions 5. Configuration Management and Documentation 6. Systems Engineering Management Plan FIGURES 1. Systems Engineering F
4、unctions 2. Systems Engineering Life-cycle Overview 3. Life-cycle Formulation Details 4. Life-cycle Implementation Details Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DIRECTIVE NO. GPR 7123.1 Page 2 of 58 EFFECTIVE DATE: October 1, 2008 EXPIRATIO
5、N DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE. GSFC 3-17 (10/04) TABLES Table 1 - Systems Engineering Key Functions Matrix APPENDICES Appendix A Systems Engineering Requirements
6、 Appendix B System Engineering Management Plan Outline Appendix C Tailoring Guidelines Appendix D Mapping of NPR Systems Engineering Processes to this GPR Appendix E Applicability of Key Functions vs. Risk Classification Appendix F Acronyms Provided by IHSNot for ResaleNo reproduction or networking
7、permitted without license from IHS-,-,-DIRECTIVE NO. GPR 7123.1 Page 3 of 58 EFFECTIVE DATE: October 1, 2008 EXPIRATION DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE. GSFC 3-17 (1
8、0/04) PREFACE P.1 PURPOSE This directive outlines a process for the systems engineering of Goddard Space Flight Center (GSFC) Missions. The intent is to outline a set of requirements that provide a consistent method for performing systems engineering across GSFC projects. The requirements for system
9、s engineering outlined in this directive are universal principles that, when followed, should result in sound systems. This directive implements NPR 7123, NASA Systems Engineering Processes and Requirements. The NPR guidelines and requirements have been tailored and refined to support the GSFC missi
10、on. A mapping of the 17 NPR systems engineering processes to this guidance is presented in Appendix D. This directive defines the minimum set of systems engineering functions for GSFC Missions. These functions, from a product perspective, are defined and described. All phases of the mission life-cyc
11、le, and systems of interest, from mission, through major system element, to subsystem, to component or assembly are considered. The systems engineering functions described in this directive are universal and generally apply across the board. What varies from project to project is who does them, to w
12、hat degree they are performed, and to what degree there is insight by the customer as to how the functions are accomplished. This directive is concerned with what must be done, along with insight into why it is done, rather than how it is done. The required functions are described by shall statement
13、s in this GPR. The referenced NASA Systems Engineering Handbook, SP-2007-6105 Rev 1, provides detailed guidance on how to perform systems engineering functions. Tailoring of how, when, where, and by whom these functions are performed is described in a project unique Systems Engineering Management Pl
14、an (SEMP). An example of a SEMP outline is listed in Appendix B. Principles for tailoring systems engineering activities are listed in Appendix C. The tailoring guidelines address who performs the functions and to what degree the functions are performed. This directive defines systems engineering te
15、rminology (Section P.10). Roles and Responsibilities (Section 1) and the systems engineering life-cycle (Section 2) are defined. Communications and the systems engineering team (Section 3) are discussed. Systems engineering functions and products, and critical function flow and process operations, a
16、re discussed in Section 4. Section 5 discusses Configuration Management (CM) and Documentation. The required plan for systems engineering implementation is given in section 6. Appendix A contains a list of the systems engineering requirements defined within this directive. It may be used as a sample
17、 validation matrix. P.2 APPLICABILITY a. This systems engineering procedure shall be applied to all GSFC managed Flight Systems (2) programmatic objectives that define the overall goals and constraints of the mission; (3) measurement concept that defines the science measurements needed to achieve th
18、e science objectives; and (4) payload concept that defines the instrument characteristics, function and performance needed to make the measurements. Mission Systems Engineer See Lead Systems Engineer Mission System Requirements (Architectural) The high-level requirements that describe the major segm
19、ents that comprise the system architecture and the key elements of each segment. For GFSC missions, a typical architecture consists of launch segment, space segment, ground segment, and science data processing segment. Objectives A set of goals and constraints that define the purpose of the mission
20、and the programmatic boundaries, and provide a basis for the Level I requirements and mission success criteria. Usually captured as Science Objectives and New Technology Validation Objectives. On Orbit Mission Success Risk Risk of not meeting on orbit mission success criteria. Operations Concept A c
21、oncept that defines how the mission will be verified, launched, commissioned, operated, and disposed of. Defines how the design is used to meet the requirements. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DIRECTIVE NO. GPR 7123.1 Page 8 of 58 EF
22、FECTIVE DATE: October 1, 2008 EXPIRATION DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE. GSFC 3-17 (10/04) Payload Concept A concept that defines the characteristics of the instrum
23、ents needed to execute the measurement concept. Product Breakdown Structure (PBS) A hierarchical tree that shows the composition of the system, sub-systems, assemblies, components, and other mission products (see Section 4.3). The PBS is used to ensure that all elements are accounted for in the desi
24、gn and development activities. Project Life cycle Formulation, Approval, and Implementation. Requirement A statement of a function to be performed, a performance level to be achieved, or an interface to be met. Requirements are indicated by the word “shall”. Requirements Document An organized hierar
25、chy of requirements that provides a validation basis for a system or system element. Risk Analysis The activity of identifying risks, and the analysis of the probability of occurrence and the consequence of occurrence. Risk Reduction The activities performed to reduce the likelihood of a risk occurr
26、ing, the consequence should the risk occur, or both. Resource Tracking The activity of tracking and maintaining technical resource allocations, estimates, and margins for system elements. Technical resources include, mass, power, volume, area, pointing accuracy and knowledge, link margin, and others
27、. Safety Risk Risk of injury to personnel, facilities or hardware. Space Environment Verification and Preparation for Deployment; and Deployment and Operations Verification. Systems Engineering Management Plan (SEMP) An implementation plan for the performance of systems engineering functions and the
28、 development of systems engineering products. This plan identifies what, when, where, by whom, and how the functions are performed. It specifies the schedule for the development, and the resources required. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
29、-,-,-DIRECTIVE NO. GPR 7123.1 Page 9 of 58 EFFECTIVE DATE: October 1, 2008 EXPIRATION DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE. GSFC 3-17 (10/04) Technical Authority The key
30、individual accountable and responsible for the technical integrity of a flight mission. Validation Proof that the Operations Concept, Requirements, and Architecture and Design will meet Mission Objectives, that they are mutually consistent, and that the “right system” has been designed. May be deter
31、mined by a combination of test, demonstration or analysis. Generally accomplished through trade studies and performance analysis by Phase B and through tests in Phase D. Validation Basis A set of requirements that provide the success criteria for a system or system element. Verification Proof of com
32、pliance with requirements and that the system has been “Designed and Built Right.” May be determined by a combination of test, analysis, demonstration and inspection. Verification Basis A set of specifications that define details of implementation, function, and performance to be verified. Provided
33、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DIRECTIVE NO. GPR 7123.1 Page 10 of 58 EFFECTIVE DATE: October 1, 2008 EXPIRATION DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THI
34、S IS THE CORRECT VERSION PRIOR TO USE. GSFC 3-17 (10/04) PROCEDURES In this document, a requirement is identified by “shall,“ a good practice by “should,“ permission by “may“ or “can,“ expectation by “will,“ and descriptive material by “is.“ 1. ROLES AND RESPONSIBILITIES a. For programs and projects
35、 involving more than one Center, the lead organization shall develop documentation to describe the hierarchy and reconciliation of center plans implementing NPR 7123.1. Systems engineering is the responsibility of all engineers, scientists, and managers working on GSFC missions since they all share
36、in the overall systems engineering effort. b. The Product Manager for the systems development function, typically a Study Manager, Project Formulation Manager, Project Manager, or Instrument Manager, shall work with the MSE Branch Head to select a Lead System Engineer. c. The Product Manager and the
37、 Lead Systems Engineer shall develop the plan for the systems engineering effort and establish a system engineering team along with roles and responsibilities. d. The Designated Governing Authority (DGA), namely, the Code 599 MSE Branch Head, shall have responsibility to approve or disapprove any re
38、quirement of this document that is either tailored or waived. This requirement, along with the associated roles and responsibilities, are captured in the SEMP (Section 6). e. The DGA, the Code 599 MSE Branch Head, shall review and approve or disapprove the SEMP at each major milestone review or its
39、equivalent. The Lead System Engineer, often referred to as the Mission System Engineer, has responsibility for the systems engineering functions and products for the overall mission. Other members of the system engineering team, discipline, subsystem, or specialty engineers have responsibility for t
40、heir part of the total effort. Product Development engineers have a responsibility to understand and apply systems engineering functions, as appropriate, to the development of their products. All have the responsibility to communicate, coordinate, and validate tasks and products across the mission.
41、The Lead System Engineer coordinates the efforts of the systems engineering team. The team recommendations are provided to the Product Manager who makes decisions that balance technical and programmatic performance. For the rest of this directive, the term system engineer will be used to represent a
42、nyone responsible for systems engineering, at any level, as defined above. 2. THE SYSTEMS ENGINEERING LIFE-CYCLE The project life-cycle is defined as a set of phases: Formulation, Approval, and Implementation. This directive defines systems engineering phases within the familiar Pre-phase A, Phase A
43、, Phase B, Phase C/D, and Phase E/F terminology, described by the NASA Systems Engineering Handbook SP-6105. Each Systems Engineering phase consists of functions and a work flow that produce the products Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-
44、,-DIRECTIVE NO. GPR 7123.1 Page 11 of 58 EFFECTIVE DATE: October 1, 2008 EXPIRATION DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE. GSFC 3-17 (10/04) needed for completion of the p
45、hase. The mission review is the validating event for the phase and may lead to a revised baseline. Figure 1, Systems Engineering Functions, shows the interrelationship of the major system engineering functions described in Section 4. Table 1, Systems Engineering Key Functions Matrix, provides a view
46、 of the evolution, in maturity and fidelity, of the systems engineering functions over the systems engineering life-cycle. Figure 2 shows the Systems Engineering Life-cycle relationship with the project life-cycle and describes the major goal of each phase. Figure 2 also shows the life-cycle phase r
47、elationship with critical milestone reviews. Figure 3 further describes the Formulation Phase. Figure 4 describes the Implementation Phase. The life-cycle accommodates the objective of systems engineering by studying multiple approaches in Pre-Phase A, conducting preliminary analysis leading to a si
48、ngle approach in Phase A, completing a preliminary design and validating that the right system has been designed in Phase B, performing a detailed design and verifying that the system is designed right in Phase C, building and verifying the system in Phase D, and operating and disposing it in Phases
49、 E and F. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DIRECTIVE NO. GPR 7123.1 Page 12 of 58 EFFECTIVE DATE: October 1, 2008 EXPIRATION DATE: October 1, 2013 CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT http:/gdms.gsfc.nasa.gov/gdmsnew/home.jsp TO V
