LAT Systems Engineering Management Plan

1 Document # Date Effective LAT-MD-00066-01 3nd Draft 1/23/01 Prepared by(s) Supersedes Tim Thurston None Warren Davis Subsystem/Office GLAST LAT PROJECT Management plan Systems Engineering Document Title LAT Systems Engineering Management plan Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Systems Engineering Management plan LAT-MD-00066-01 LAT Systems Engineering Management plan Page 2 of 29 CHANGE HISTORY LOG Revision Effective Date Description of Changes DCN # 1 Initial Release LAT-CN-000xx LAT-MD-00066-01 LAT Systems Engineering Management plan Page 3 of 29 CONTENTS 1 Purpose and Scope .. 5 2 Acronyms .. 5 3 Applicable Documents .. 6 4 Systems Engineering 7 Organizational Responsibilities and Relationships .. 7 Systems Engineering Process Planning .. 8 Major Systems Engineering Products.

2 8 Technical Objectives .. 10 Work Breakdown 10 Work Authorization .. 10 Verification: Integration and Test Plans .. 11 Participants .. 11 Requirements 12 12 Engineering Considerations .. 12 Allocated Requirements .. 12 Review Process .. 13 system Analysis .. 13 Trade 14 Cost Effectiveness Analyses .. 14 system 14 Risk 14 Configuration Management .. 15 Interface 15 Technical Performance Metrics (TPMs) .. 15 Technical Reviews .. 16 Supplier Control .. 17 Requirements Traceability .. 17 5 Implementation .. 18 Integration of Systems Engineering Effort .. 18 LAT-MD-00066-01 LAT Systems Engineering Management plan Page 4 of 29 Problem Resolution .. 18 Systems Engineering Plans and 18 6 Other Systems Engineering Activities.

3 19 Long Lead Items .. 19 Engineering Tools .. 19 Requirements Management Software .. 19 Database 20 20 APPENDIX A .. 21 LAT Level III Specification Review/Release Description and Charge .. 21 APPENDIX B .. 25 Technical Review Definitions and Checklists .. 25 system Requirements Review (SRR) .. 25 Preliminary Design Review (PDR) .. 26 Critical Design Review (CDR) .. 27 Test Readiness Review (TRR) .. 28 Pre-Shipment Readiness Review (PSRR) .. 29 LAT-MD-00066-01 LAT Systems Engineering Management plan Page 5 of 29 1 Purpose and Scope This Systems Engineering Management plan (SEMP) describes the activities, processes, and tools that will by used by the GLAST Large Area Telescope (LAT) Systems Engineering team to support the design and construction of the LAT instrument and Instrument Operations Center. The objective of the Systems Engineering effort is to assure successful development of the LAT system primarily by defining clear and accurate system requirements and verifying compliance of the system to those requirements.

4 The LAT system consists of the Science Instrument (SI) and the Instrument Operations Center (IOC). The SI is a space-borne detector capable of measuring the direction and energy of incident cosmic gamma rays. The IOC is the ground-based facility that controls the operation of the SI and records and processes its raw data. This SEMP is applicable to all Systems Engineering tasks to be performed in support of the LAT project. This document will be placed under change control upon its initial release. 2 Acronyms ACD Anticoincidence Detector CAL Calormeter CCB Change Control Board CDR Critical Design Review CEA Commissariat l'Energie Atomique CMP Configuration Management plan DAPNIA D partement d'Astrophysique, de physique des Particules, de physique Nucleaire et de L Instrumentation Associ e E/PO Education and Public Outreach GLAST Gamma-ray Large Area Space Telescope GSFC Goddard Space Flight Center IN2P3 Institut National de Physique Nucleaire et de Physique des Particules INFN Istituto Nazionale di Fisica Nucleare, Italy IOC Instrument Operations Center IPI Instrument Principal Investigator IPM Instrument Project Manager IPO Instrument Project Office ISE Instrument Systems engineer KTH Royal Institute of Technology.

5 Sweden LAT Large Area Telescope LAT-MD-00066-01 LAT Systems Engineering Management plan Page 6 of 29 LOF LAT Operations Facility NRL Naval Research Laboratory PAIP Product Assurance Implementation plan PAPL Program Approved Product List PDR Preliminary Design Review PER Pre-Environmental Review PFR Problem/Failure Report PSR Pre-Shipment Review RMP Risk Management plan SAS Science Analysis Software SEMP Systems Engineering Management plan SI Science Instrument SLAC Stanford Linear Accelerator Center SRR system Requirements Review SSAC Senior Scientist Advisory Committee SSRR Subsystem Requirements Review SSU Sonoma State University SU Stanford University SU-HEPL Stanford University High Energy Physics Lab T&DF Trigger and Dataflow TKR Tracker TPM Technical Performance Metric UCSC University of California at Santa Cruz WBS Work Breakdown Structure 3 Applicable Documents The following documents are applicable to the development of this SEMP.

6 GLAST00110, Mission Assurance Requirements (MAR) for Gamma-Ray Large Area Telescope (GLAST) Large Area Telescope (LAT) , June 9, 2000 GEVS-SE Rev A, General Environmental Verification Specification for STS & ELV Payloads, Subsystems, and Components , GLAST Large Area Telescope Flight Investigation: An Astro-Particle Physics Partnership Exploring the High-Energy Universe , proposal to NASA, P. Michelson, PI, November, 1999. LAT-MD-00066-01 LAT Systems Engineering Management plan Page 7 of 29 4 Systems Engineering Process Organizational Responsibilities and Relationships The LAT team consists of members from several geographically diverse organizations and is managed by the LAT Instrument Project Office (IPO) at Stanford Linear Accelerator Center (SLAC). The Instrument Systems engineer (ISE), who is part of the IPO and reports to the Instrument Project Manager (IPM), manages and is responsible for the Systems Engineering activities.

7 The organizational structure of the LAT collaboration is shown in Figure 1. The ISE provides technical leadership and directs the work of the subsystem development teams through the development and tracking of requirements, reserves, interface control documents, and performance and verification specifications. The ISE is responsible for assuring that the subsystems are compatible and meet the overall objectives. The ISE also oversees, from the instrument side, all aspects of the spacecraft/instrument interfaces. Figure 1: LAT Organization Chart system Engineer (ISE) SLAC Integration & Test SLAC Mech. Systems SLAC Project Controls SLAC Performance & Safety Assurance SLAC Principal Investigator (IPI) SU Project Manager (IPM)SLAC Instrument Design Team SLAC Sci. Software SLAC IOC SU CAL NRL, France, SwedenTKR UCSC, SLAC, Italy, Japan ACD GSFC Instrument Scientist GSFC E/PO SSU SSAC GSFCC ollaboration Science TeamElectronics & DAQ SLAC IPO LAT-MD-00066-01 LAT Systems Engineering Management plan Page 8 of 29 The subsystem organizations provide support to the project Systems Engineering effort through development of subsystem level specifications and test plans and overseeing the subsystem-level verification process.

8 Systems Engineering Process Planning This section describes the key components of the LAT Systems Engineering process, including the major Systems Engineering products, technical objectives, work breakdown structure, requirements verification, and Engineering participants. Major Systems Engineering Products Integrated Database Throughout the design phase of the LAT project, many studies and analyses will be conducted to support decisions regarding requirements selection and system design. The collection of these reports effectively documents the process of defining the LAT system and will be archived for future reference. As requirements and specifications are recorded in the requirements database, they will be linked to the applicable analyses to provide traceability to the rationale for the requirements. By providing the original context in which a requirement was selected, any future reconsideration of the requirement can determine if the original constraints are still valid.

9 Baselines Throughout the lifecycle of the project, the LAT system configuration is defined in a series of technical baselines, consisting of the approved documentation used to define the technical requirements and interfaces. These baselines define the characteristics of the LAT system , subsystems, software and equipment at different development stages of the project. The technical baseline progresses from high-level requirements (the Functional Baseline) to more detailed requirements, design drawings and specifications (the Allocated Baseline) to complete as-built manufacturing drawings and specifications (the Product Baseline). Specifications, interface control documents, and drawing packages are used to design and fabricate or procure items. These baseline documents will be organized in a hierarchy that provides design traceability to the lowest level. Once approved, these baseline documents are placed under configuration control, as described in the Configuration Management plan (CMP).

10 Specifications The planned specification tree, Figure 2, shows the allocation of specifications to the functional units of the LAT organization. The specification tree also represents the flow of requirements from the top-level mission requirements to increasingly detailed requirements for the subsystems. The specifications are grouped into levels within the context of the GLAST project. The LAT instrument and IOC are two elements of the GLAST system . The high-level mission specifications are developed by the GLAST Project Office. The levels of specifications developed and controlled by the LAT Project are: Elements, Level II(b): The Level II(b) specifications contain the high-level performance requirements for the SI and IOC. These specifications are the LAT-MD-00066-01 LAT Systems Engineering Management plan Page 9 of 29 responsibility of the ISE. Changes to these specifications require approval of the Configuration Control Board (CCB) and GSFC.