This page is a compendium of changes since the rollout of NPR7150.2C and includes notations of the changes from 2B to 2C. This page will be maintained only in the SITE Resources space to avoid problems with duplication and making changes in the wrong page. Redirection in SWEHBVC and SWEHBVD will bring you here for adding content. 

Change History

Completed Work 

Completed work since the changes from NPR 7150.2B to NPR7150.2C. Includes the addition of substantial Software Assurance and Safety material. 

 1. To coincide with the release of NPR 7150.2C (on 8/2/2019), the following large changes were made to the Handbook:

  • All software requirements were updated from NPR 7150.2B to NPR 7150.2C (124+ pages)
  • All guidance corresponding to software requirements was reviewed and updated (124+ pages)
  • All references were reviewed and updated
  • SWEs retired: 22
  • SWEs reserved: 27 (not used in drafts but issued in final version)
  • Created "applicable-c" macro for use in in tab 1 of all project SWEs (replaces "applicable-b" macro. 

 2. In anticipation of the release of NASA-STD-8739.8 (late 2019 and early 2020), a software assurance tab was added to each NPR 7150.2C requirements page (from Chapters 3 through 5). (Total of 110 pages) Each page contains:

  • Corresponding NPR requirement
  • Software Assurance Required Tasks from NASA-STD-8739.8
  • Expected Product(s) from Performing Tasks
  • Suggested Metrics from Performing Tasks
  • Guidance on How to Perform Tasks

 3. Updates to the Software Engineering Topics

Multiple changes to existing Topics. Two Topics were added and two were retired. 

  • 7.2 was modified to have the new criteria for classifying software as safety- critical (7/2020)
  • 7.8 (Maturity of Life Cycle Products at Milestone Reviews) was modified (6/2020) to add Maturity of Software Assurance and Safety Products at each Major Milestone review
  • 7.9 (Entrance and Exit Criteria) was updated (6/2020) to include software assurance and safety entrance and exit criteria for each major review.
  • 7.10 (Peer Reviews and Inspections Including Checklists)was updated (5/2020)
  • 7.11 (SWE History) was added to list the current status of all the requirements appearing in NPR 7150.2A, NPR7150.2B and NPR 7150.2C. Each requirement number references the location on the requirement page that describes the detailed history of the particular requirement (217 pages) (7/2020)
  • 7.18 (Documentation Guidance) modified (2/2020) to add documentation guidance (recommended guidance) for the following Software Assurance and Safety documents:
    1. SAANALYSIS – Software Analysis on the Detailed Software Requirements
    2. SADESIGN - Software Assurance Design Analysis
    3. SAP – Software Assurance Plan
    4. SASTATUS – Software Assurance and Software Safety Status Reports
    5. SSP – Software Safety Plan\
  • 7.19 (Risk Management Checklists) new topic added (1/2020). Contains software checklists for planning, requirements, design, implementation, testing, release, operations and maintenance and other risks.
  • 7.21 (Multi-Condition Software Requirements) new topic added (2/2021). Provides recommendations on handling and testing software with multiple condition requirements.

 4. Added a new tab to the "D. Topics" page titled "Assurance and Safety Topics".

A total of 18 topics were added:

  • 8.1 Off Nominal Testing (1/2020)
  • 8.2 Software Reliability (6/2020)
  • 8.3 Organizational Goals of Software Assurance Metrics (1/2020)
  • 8.4 Additional Requirements Considerations for Use with Safety-Critical Software (5/2020)
  • 8.5 Software Failure Modes and Effects Analysis (1/2020)
  • 8.6 IV&V Surveillance (6/2020)
  • 8.7 Fault Tree Analysis (1/ 2020)
  • 8.8 COTS Software Safety Considerations (6/2020)
  • 8.9 Software Safety Analysis (6/2020)
  • 8.10 Facility Software Safety Considerations 6/2020)
  • 8.11 Auto-Generated Code (1/2020)
  • 8.12 Basics of Auditing (1/2020)
  • 8.13 Test Witnessing (6/2020)
  • 8.14 SA Tasking for NPR 7150.2B (6/2020)
  • 8.15 SA Checklist Tool (10/2020)
  • 8.16 (Placeholder for SA Products)
  • 8.17 (Placeholder for Confirmations)
  • 8.18 SA Suggested Metrics (4/2021)

 5. Added a new tab (8/2020) to the "D. Topics" page titled, “Software Design Principles.”

These Principles were moved from the SPAN server. There are 17 principles pages, each containing:

  • The Principle
  • Example and Discussion
  • Inputs from Centers Relating to the Principle
  • Resources
  • Lessons Learned
  • Coding Standards
  • Command Receipt Acknowledgement
  • Data Interface Integrity
  • Dead Code Exclusion
  • Fault Detection and Response
  • Flight Software Modification
  • Incorrect Memory Use or Access
  • Initialization - Safe Mode
  • Invalid Data Handling
  • Resource Margins
  • Resource Oversubscription
  • Resource Usage Measurement
  • Safe Transitions
  • Thread Safety
  • Toggle Commands

 6. Added a new tab (4/2021) to the "D. Topics" page titled, “Programming Checklists”

This tab consists of  10 checklists and a file with good and Bad Exception Handling Practices.


  • General Software Safety Requirements
  • Checklist for Choosing a Real Time Operating System (RTOS)
  • Checklist for Choosing Off-the Shelf Software (OTS)
  • Checklist for C Programming Practices
  • Checklist for C++ Programming Practices
  • Checklist for Ada Programming Practices
  • Checklist for Fortran Programming Practices
  • Checklist for Generic (Non-Language Specific) Programming Practices
  • General Good Programming Practices
  • Examples of Programming Practices for Error Handling

 7. Added FAQ (Frequently Asked Questions) section with questions and answers for software engineering, software assurance and safety areas. (10/2020, updated 2/2021,3/2021)

  • Includes tabs for:
    • Engineering Questions – 0 questions
    • Software Assurance Questions – 6 questions
    • Safety Questions – 9 questions
    • Questions common to all areas – 5 questions 

 8. Reformatted all “lesson Learned” pages to include lessons learned from other sources as well as the from the database (100+ pages)

Reformatted all pages to adhere to a common presentation of information

  • Lessons Learned database
  • Other Lessons Learned resources

 9. Changed Section E: Tools, References and Terms:

  • Reformatted Terms Database
  • Reformatted Acronyms database
  • Reformatted Tools Table
  • Added approximately 60 new References

10. Added the capability to link into earlier versions of the SWE Handbook: (9/2020)

  • Added “Accessing Other Versions of SWEHB” tab in all 3 versions of SWEHB 

Work in Progress - 2021 - 2022

Work in Progress will be moved into the Completed Work tab once it is finished, reviewed, and approved for release. 

 1. Implement SA Metrics for topic 8.18 (April and May 2021)

  • Update Topic 7.18 with SA Life Cycle Products -
    • Converted spreadsheet into text format for display in the Topic. 
    • Attach spreadsheet to Topic 8.18
  • Update all SWEs with metrics. Put metrics from the spreadsheet into Tab 7.3 - Metrics (Count of SWEs affected)
  • Update Topic 8.18
    • Add text version of spreadsheet into tab 2,
    • link to Excel spreadsheet attached to topic. 
  • Coordinated metrics in each requirement with metrics in Master metrics file and added any missing metrics to the appropriate requirement (early August, 21

 2. Other ongoing modifications, minor rewordings, and clarifications 

  • Modifications from NESC assessments
  • Additional Lessons Learned
  • Modify / remove references to "Classification Tool" in all three versions of SWEHB (July 2021)
  • Clean up tables of referenced SWEs and Topics in tab 3 of most SWEs in all three versions (July - August 2021)
  • Added definition of Integration testing to Topic 7.21; added risk probability, risk severity to risk metrics in Topic 7.14, Tab 2

3. Add Objective Evidence in all SWEs with SA tabs (May 2021)

  • Add macros for Note box and definition of Objective Evidence
  • Add content for Objective Evidence Notes 

 4. Add various new Topics

 5. Build out topic 8.16 - SA Product List (August through Dec 2022) 

  • Designed areas for SA Products, consisting of an Introductory Page that has links to each of the nine major products plus one for objective evidence.
  • Introductory Page is complete and has 2 completed tabs, one that maps the products and sub-products to milestones, and one that maps the products to the SASS Task in NASA-STD-8739.8
  • Pages have been built with the planned tabs for each product.
  • Software Assurance Plan is populated with the Introduction and tabs for SA Plan content and Safety Plan Content.  Security Plan and Resources-TBS
  • IV&V Project Plan is populated with Introduction, and tabs for Content, PRBA/RBA. Resources tab-TBS
  • Software Requirements Analysis (5 tabs total, 4 populated-Introduction, Requirements Analysis Techniques, Safety Requirements Analysis, Reporting Results)
  • SA Status Page will be Introduction, Status Contents (Done), and additional tabs (in-work)
  • Safety and Hazard Analysis (4 tabs TBS)
  • Software Design Analysis (4 tabs total, completed and under review)
  • Software Code Quality Analysis (5 tabs completed and under review)
  • Software Testing Analysis (4 tabs TBS)
  • Objective Evidence (4 tabs complete)
  • Audit Report (5 tabs total, Introduction, Audit Page, Audit Metric Page, Audit Results complete, under review, Checklist matrix TBS)

 6. Created SWE History pages for all SWEs in all versions of the SWEHB (2021)

  • Pages with the history, by version, are in SITE space
  • All SWE pages in the current version of SWEHB have a section 1.2 History section with a link to the SWEs history page
  • Covers up to SWE-223

Work in SWEHBVD - 2022

Includes preparation of the space for release as well as work unique to SWEHBVD and versions moving forward. 

 1. Create SWEHBVD based on SWEHBVC ( August 2021 thru April 2022)

  • Create space and copy all content from VC to VD
  • Create Theme for SWEHBVD with DRAFT in the header image
  • Update internal links to ensure that they point within the SWEHBVD space
  • Retire 4 SWEs
  • Add new SWEs, including History pages - SWE-208, 209, 210, 212, 219, 220, 221, 222, 223
  • Update SWEs and Notes from NPR 7150.2D as necessary
  • Released new version SWEHBVD in April, 2022

 2. Move shared resources to SITE Resources space (August 2021 thru 2022)

Certain resources are shared among SWEHB versions. This shared content is best contained in SITE space so that changes are immediately available in all SWEHB versions. 

  • Definition of Objective Evidence page moved from SWEHBVC and SWEHBVD to SITE. Updated all SWEs in two version spaces to point to the page in SITE (approximately  250 pages)
  • Moved Change History to SITE - Put redirection pages in SWEHBVC and SWEHBVD
  • Moved Doc Structure References reports to SITE
  • Analyzing Topics to see if some are independent of NPR version and can be moved to SITE space

 3. Document SWEHB collection of spaces in SITE (September 2021 thru 2022)

  • Documents overall architecture for all versions of SWEHB
  • SWEHB Style Guide
  • Topics Style Guide
  • User Macro documentation

4. Formatting changes in SWEs and Topics (January 2022 - July 2022)

  • Replace Panel macros with Note macro. This makes the item standout better: in yellow boarder box, with yellow background and Note icon. 
  • Add link to SPAN for SWEs and topics that reference SPAN libraries. Add link to SWEREF-197. 
  • Implement new Panel macro for large quotations. 
    • Quotes of one complex sentence or larger, are put in a blue panel,  
  • General cleanup of sub-headings for all pages

5. Checklists and Guidance Assets  & Process Asset Templates (2022 )

  • Started in SWEHBVC, and carrying over into SWEHBVD. Checklists and other guidance assets buried in SWEs and topics are listed in a table in the "Checklists and Guidance Lists" page, under topic "8.16 - SA Products". 
  • Built "pat" template for PAT pages - reused code in "references" template
  • Built reports pages for new PATs where PATs can be called out in pages just like References
  • Built PAT Database in SITE to contain all PATs - reused structure from References 
  • Added new Category of assets reports for grouping PATs in meaningful collections
  • PAT count: 30 as of 10/19/2022 

6. Changes for NASA-STD-8739.8B (June 2022 - December 2022)

  • Built a copy of NASA-STD-8739.8B in SITE. Include pages derived from this document are child pages under this document
  • Updated all the sections in Topic 8.16 that include tasks from NASA-STD-8739.8 with latest latest version NASA-STD-8739,8B
  • Updated all Tab 7.1 (SWEs from NPR Chapter 3) with tasks from NASA-STD-8739.8B - put in quote boxes (blue border)
  • Built include pages for all SA Tasks and all Requirements in sections 4.4.2 and 4.5

7. New Topics, Updated Guidance (2022)

  • New Topic added: 8.23 Software Contents for a Certification for Flight Readiness Review (CoFR) (July 2022)

  • Review comments from NESC Test and Validation Team  added to 8.16 Testing Analysis (August 2022)
  • 2 Checklists from NESC Test and Validation Team added to SWE-066: Test Review Checklist for Test Team Leads, and Test Review Checklist for Test Reviewers or Review Panel Members (July 2022)
  • Checklist for Detection of Adversarial Actions added in SWE-210 (July, 2022)
  • List of Tools for Code Coverage added to SWE-220 (August 2022)

Work in 2023

1. New Activity View and Improvements (October 2022 - ?)

  • Planning for Activity View of SWEHBVD content - reviewed at SwWG meeting, Feb, 2023 at KSC (Feb 2023)
  • Reorganization of Requirements Buttons and Pages (Mar 2023)
    • Add a way to see all SWEs in numeric order
    • Revise top block of text to include expand sections

2. Reformatting SWEHB pages (2023)

  • Addition of a blog for SWEHBVD in Introduction page and "New in SWEHB" link to History page ( Feb 2023)
    • Link for "New in SWEHB" added to major pages
  • Add "Related Links" table to all appropriate pages ( Feb - June 2023)
    • SWEs - in tab 3 and tab 7
    • Topics - depends on the tab layout
  • Subheadings in all SWEs, tab 3 (Jan - March 2023)
  • Add "Center Process Asset Libraries" section to SWEHBVD - includes note about SPAN, link to SPAN in NEN, SPAN links to appropriate SPAN page based on the subject matter of the SWE or Topic ( Feb - June 2023)
    • SWEs - in tab 3 and tab 7
    • Topics - depends on the tab layout
  • Add "Associated Activity" section ( Feb - June 2023)
    • SWEs - in tab 1 - hidden until formal rollout of activities
    • Topics - in Resources tab
  • Buildout of Activity pages as additional view of SWEs, Topics and other related materials based on Life Cycle phases (Mar 2023 - In Progress 2023)

3. New Topics, Updated Guidance (2023)

4. Checklists and Guidance Assets  & Process Asset Templates (2023 )

  • Built list of ToDo items into PAT ToDo List page - includes completed PATs as well as PAT content found in SWEHBVD pages that could be converted into a PAT

5. Document SWEHB collection of spaces in SITE (2023)

6. Topic changes (2023)

  • Renumber topics into a 4 character prefix in the title to facilitate use of references macros (eliminate special key word and extra coding to build references table)
    • Completed work in SWEHBVD, SWEHBVC, SWEHBVB, 7150 - July 2023
    • Pages that were re-titled nave a copy of the old page with a redirect to the new page s that old links and bookmarks will get users to the correct new page
  • Planning for Generic Topics - These will be located in SITE and be applicable to all versions of the SWEHB. They will not contain links to other SWEHB version pages. 
    • Reformatting topics that are not specific to a particular version of SWEHB. Includes removing links and putting the page into SITE space while keeping an "Include-Page" macro in the SWEHB space  so that the space header of properly retained. 
    • Topic 8.24 is the first Generic Topic - implemented in SWEHBVD. 

7. Blog entries in 2023

Work in 2024

1. Continuation of New Activity View and Improvements (October 2022 - ?)

  • Complete crosslinking Topics and SWEs for SWEHBVD

2. Reformatting SWEHB pages (2024 -)

  • Buildout of Activity pages as additional view of SWEs, Topics and other related materials based on Life Cycle phases (Mar 2023 - In Progress )

3. New Topics, Updated Guidance (2024)

  • Updates to Guidance for SWE-050. SWE-051 and SAANALYSIS (October 2024 - In Progress)
  • Topic 7.17 - 7150.2D Appendices (Definitions, References, etc.) enhanced to include Appendix B Acronyms and Appendix E References from NPR 7150.2D. Previously it had only the Definitions from the NPR. 

4. Checklists and Guidance Assets  & Process Asset Templates (2023/2024)

  • PAT ToDo List page - includes completed PATs as well as PAT content found in SWEHBVD pages that could be converted into a PAT

5. Document SWEHB collection of spaces in SITE (2023/2024)

6. Topic changes (2024)

  • Continue implementing Generic Topic Pages in SWEHBVD. 

7. Blog entries in 2024

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