ESA PSS-05-07 Issue 1 Revision 1 March 1995 Guide to the software operations and maintenance phase Prepared by: ESA Board for Software Standardisation and Control (BSSC) Approved by: The Inspector General, ESA european space agency / agence spatiale européenne 8-10, rue Mario-Nikis, 75738 PARIS CEDEX, France ii ESA PSS-05-07 Issue 1 Revision 1 (March 1995) DOCUMENT STATUS SHEET DOCUMENT STATUS SHEET DOCUMENT STATUS SHEET 1. DOCUMENT TITLE: ESA PSS-05-07 Guide to the Software Operations and Maintenance Phase 2. ISSUE 3. REVISION 4. DATE 5. REASON FOR CHANGE 1 0 1994 First issue 1 1 1995 Minor updates for publication Issue 1 Revision 1 approved, May 1995 Board for Software Standardisation and Control M. Jones and U. Mortensen, co-chairmen Issue 1 approved, 15th June 1995 Telematics Supervisory Board Issue 1 approved by: The Inspector General, ESA Published by ESA Publications Division, ESTEC, Noordwijk, The Netherlands. Printed in the Netherlands. ESA Price code: E1 ISSN 0379-4059 Copyright © 1995 by European Space Agency ESA PSS-05-07 Issue 1 Revision 1 (March 1995) iii TABLE OF CONTENTS TABLE OF CONTENTS CHAPTER 1 INTRODUCTION..................................................................................1 1.1 PURPOSE .................................................................................................................1 1.2 OVERVIEW................................................................................................................1 CHAPTER 2 THE OPERATIONS AND MAINTENANCE PHASE ............................3 2.1 INTRODUCTION.......................................................................................................3 2.2 OPERATE SOFTWARE.............................................................................................6 2.2.1 User support ...................................................................................................6 2.2.2 Problem reporting..............................................................................................7 2.3 MAINTAIN SOFTWARE ............................................................................................9 2.3.1 Change Software.............................................................................................10 2.3.1.1 Diagnose Problems...............................................................................11 2.3.1.2 Review Changes....................................................................................14 2.3.1.3 Modify Software.....................................................................................17 2.3.1.3.1 Evaluating the effects of a change.............................................17 2.3.1.3.2 Keeping documentation up to date ...........................................21 2.3.1.4 Verify software modifications ................................................................22 2.3.2 Release Software.............................................................................................23 2.3.2.1 Define release........................................................................................23 2.3.2.2 Document release .................................................................................25 2.3.2.2.1 Release number..........................................................................25 2.3.2.2.2 Changes in the release...............................................................26 2.3.2.2.3 List of configuration items included in the release ....................26 2.3.2.2.4 Installation instructions ...............................................................26 2.3.2.3 Audit release..........................................................................................26 2.3.2.4 Deliver release .......................................................................................27 2.3.3 Install Release .................................................................................................27 2.3.4 Validate release................................................................................................27 2.4 UPDATE PROJECT HISTORY DOCUMENT..........................................................28 2.5 FINAL ACCEPTANCE.............................................................................................28 CHAPTER 3 TOOLS FOR SOFTWARE MAINTENANCE......................................31 3.1 INTRODUCTION.....................................................................................................31 3.2 NAVIGATION TOOLS .............................................................................................31 3.3 CODE IMPROVEMENT TOOLS .............................................................................32 3.4 REVERSE ENGINEERING TOOLS.........................................................................33 CHAPTER 4 THE PROJECT HISTORY DOCUMENT............................................35 4.1 INTRODUCTION.....................................................................................................35 4.2 STYLE......................................................................................................................35 iv ESA PSS-05-07 Issue 1 Revision 1 (March 1995) PREFACE 4.3 EVOLUTION............................................................................................................35 4.4 RESPONSIBILITY....................................................................................................35 4.5 MEDIUM .................................................................................................................35 4.6 CONTENT...............................................................................................................35 4.6.1 PHD/1 DESCRIPTION OF THE PROJECT......................................................36 4.6.2 PHD/2 MANAGEMENT OF THE PROJECT....................................................37 4.6.2.1 PHD/2.1 Contractual approach ...........................................................37 4.6.2.2 PHD/2.2 Project organisation ..............................................................37 4.6.2.3 PHD/2.3 Methods and tools ................................................................37 4.6.2.4 PHD/2.4 Planning.................................................................................38 4.6.3 PHD/3 SOFTWARE PRODUCTION ................................................................38 4.6.3.1 PHD/3.1 Product size............................................................................38 4.6.3.2 PHD/3.2 Documentation.......................................................................39 4.6.3.3 PHD/3.3 Effort........................................................................................39 4.6.3.4 PHD/3.4 Computer resources ..............................................................39 4.6.3.5 PHD/3.5 Productivity .............................................................................39 4.6.4 PHD/4 QUALITY ASSURANCE REVIEW.........................................................40 4.6.5 PHD/5 FINANCIAL REVIEW ............................................................................41 4.6.6 PHD/6 CONCLUSIONS...................................................................................41 4.6.7 PHD/7 PERFORMANCE OF THE SYSTEM IN THE OM PHASE....................41 CHAPTER 5 LIFE CYCLE MANAGEMENT ACTIVITIES .......................................43 5.1 INTRODUCTION.....................................................................................................43 5.2 SOFTWARE PROJECT MANAGEMENT................................................................43 5.2.1 Organisation .................................................................................................44 5.2.2 Work packages................................................................................................44 5.2.3 Resources .................................................................................................45 5.2.3.1 Lehman's Laws......................................................................................46 5.2.3.2 Code size maintenance cost estimating method ................................47 5.2.4 Activity schedule..............................................................................................47 5.3 SOFTWARE CONFIGURATION MANAGEMENT ..................................................47 5.4 SOFTWARE VERIFICATION AND VALIDATION....................................................47 5.5 SOFTWARE QUALITY ASSURANCE .....................................................................49 APPENDIX A GLOSSARY ....................................................................................A-1 APPENDIX B REFERENCES................................................................................B-1 APPENDIX C MANDATORY PRACTICES ...........................................................C-1 APPENDIX D INDEX.............................................................................................D-1 ESA PSS-05-07 Issue 1 Revision 1 (March 1995) v PREFACE PREFACE This document is one of a series of guides to software engineering produced by the Board for Software Standardisation and Control (BSSC), of the European Space Agency. The guides contain advisory material for software developers conforming to ESA's Software Engineering Standards, ESA PSS-05-0. They have been compiled from discussions with software engineers, research of the software engineering literature, and experience gained from the application of the Software Engineering Standards in projects. Levels one and two of the