A WebBased Process and Process Models to Find and Deliver Information to Improve the Quality of Flig

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A Web-Based Process and Process Modelsto Find
and Deliver Informationto Improve the Qualityof
Flight Software

• J. Scott Hawker
• Hong Ma
• Randy K. Smith
• The University of Alabama
• Tuscaloosa, Alabama

Supported by grants from the NASA Marshall Space
Flight Center Flight Software Group (ED14) NASA
Technical Standards Program (ED41)
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Abstract

• Aerospace systems demand high-quality software
  engineering processes to deliver high-quality
  products
• Many processes fail to deliver the organizations
  wealth of information and experience that can
  contribute to product and process quality
• We present a web-based process support tool that
  delivers
• Information in a flight software engineering
  process
• Associated standards, lessons learned, and
  background information
• The tool is based on an underlying formal model
  of the software engineering process activities
  and artifacts
• A semantic basis for context-based search and for
  reasoning about the engineering process
• Result information portal to search for and
  deliver process and project-specific information
  to support flight software development

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Process Web Site Snapshot 1
Process Info
Link to Standards, Lessons, Background
Link to Artifacts, Templates, Support Info
Search for Standards and Lessons
Navigate by Activity Structure
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Process Web Site Snapshot 2
Access to Normal Text Process Document
Keyword Search
Detailed Process Info
Process Info in Consistent Structure
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Capture New Lessons
Capture New Lessons for Later Use
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Underlying Model of Process

• A semantic model of the software engineering
  process underlies the user-visible web pages
• Web pages are a visualization of the underlying
  model of activities and work products
• The underlying semantic model drives software
  agents (such as search and workflow engines) that
  use the underlying model to augment the user
  interaction
• The underlying model enables

• Semantic-based search for activity-relevant
  standards and lessons learned
• Formal reasoning about activity specifications
  and reusable work products
• Dynamic assembly and tailoring of process
  elements from reusable process components

• Process automation
• Assurance of process conformance
• Reasoning about process usage metrics and process
  improvement opportunities
• etc.

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Definition Process and Activity

• A process is a collection of activities executed
  and coordinated to achieve goals
• Activities produce a result (output) by acting
  upon one or more inputs
• Inputs and outputs are data and/or physical
  objects (documents, materials, etc.) involved in
  an activity
• Inputs serve different roles in the activities
• Some inputs are consumed or transformed to
  produce outputs
• Some inputs are guidance or control on how an
  activity is performed
• Associated with an activity are resources or
  mechanisms that perform the activity

Guidance or Controls
Activity
Outputs
Inputs
Resources or Mechanisms
Based on IDEFØ and SPEM
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NASA ED14 Preliminary Software Design Activity

• NASA-STD-2201-93
• NASA-STD-8719.13A
• NASA-GB-1740.13-96
• IEEE-1016
• IEEE-1016.1
• IEEE-12207.1

• Software Requirements Spec.
• Hardware Design Concepts
• Interface Control Doc.
• Trade Studies

Prelim. Software Design

• Preliminary Software Design Description
• Trade Studies

• Software Design Team
• Project Development Team

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Subactivities of ED 14 Software Design Activity
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Process Definition, Enactment, and Execution
Process Models
Process Design and Definition
Activity Instantiation and Control
Activity Enactment
Engineering Tools and Information
Activity Execution
From OMG Workflow Management
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Toward a Software Engineering Process Ontology

• Based on
• IDEF
• OMG Software Process Engineering Metamodel
• OMG Workflow Management
• Other software engineering models

Packages in the ontology
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Basic Elements Package

• All model elements can have
• Guidance
• External description

PresentationElement is a human
Element
readable textual and graphical
notation for the corresponding model
elements.
subject
ModelElement
presentation
PresentationElement
name Name
0..
0..
0..
0..
1..
1..
annotatedElement
0..
0..
ExternalDescription
- name String
description
- location String
0..
guidance
0..
- content String
kind
guidance
GuidanceKind
Guidance
- medium String
0..
0..
1
1
- language String
GuidanceKind examples technique,
Specializes
directive, checklist, tool mentor, guideline,
"presentation" role of
template, estimate, etc.
location URI (file path, URL, etc.)
ModelElement
medium format (MIMEtype?)
language English, Japanese, etc.
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EnactmentPackage

• Mechanisms to
• Start and complete a specific instance of an
  activity
• Record history about that activity instance

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Activities Package
Models the three key elements of processes
Person (role) performing an Activity to produce a
Product
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Modeling and Implementation Languages

• We use the Unified Modeling Language (UML) as the
  basic knowledge representation language for the
  underlying model
• A precise, yet understandable, way to represent
  and visualize knowledge
• From these UML models, we derive and translate
  between numerous concrete representations that
  implement the models as computer data structures
  and programs
• Java and Perl language programs
• HTML files and JavaScripts interpreted by a web
  browser
• XML streams that are interpreted by XML
  Stylesheet definitions for user display and
  interaction
• XML streams are created and manipulated by Java,
  C, and Perl programs

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Model-Driven ED14 Web Portal

• Instantiate the activity model for the NASA ED14
  process
• Activity aggregation hierarchy
• Activity descriptions text, web page, and flow
  diagram
• Input and output WorkProducts for an Activity
• Guidance elements for an Activity
• Standards, lessons learned, templates, etc.
• Model-driven ED14 web pages
• Drive the web portal using implementations of the
  model class instances
• Write scripts to generate web pages with a
  database-driven, dynamic approach
• The web pages are a visualization of the
  underlying model of roles, activities, and work
  products
• The underlying semantic model drives and augments
  the user-interactive web pages

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Activities for NASA ED14 Process
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Activity Descriptions
ExternalDescription
Plain text
name Text Description
location file//cs.ua.edu/.
description
content The Preliminary Software
Design phase will begin
format text/plain
language eng
subject
subject
ExternalDescription
name Web Page Description
Web page
subject
location http//cs.ua.edu/.
content lthtmlgt ltheadgt
ltmetagt lt/headgt

• Graphical elements for user interfaces or
  generated documents
• For search and reasoning, knowing the names,
  types, and relationships among the specific
  elements is valuable

description
format text/html
language eng
Flow diagram
ExternalDescription
name Flow Diagram Web Page
location http//cs.ua.edu/.
content lthtmlgtprelimDesign.jpeg
description
format text/html
language eng
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Input and Output WorkProducts to an Activity
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Guidance Elements for an Activity
guidance
guidance
guidance
guidance
guidance
guidance
guidance
annotatedElement
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Implement Activity Model with XML
lttreegt ltbranch iddesigngt ltbranchTextgtSoftware
Designlt/branchTextgt ltleafgt ltleafTextgtDescripti
onlt/leafTextgt ltlinkgt\design.htmllt/linkgt lt/leafgt
ltbranch iddesignsubgt ltbranchTextgtSub
Activitieslt/branchTextgt ltbranch
idPredesigngt ltbranchTextgtPreliminary
Designlt/branchTextgt ltleafgt ltleafTextgtDescriptio
nlt/leafTextgt ltlinkgt\Predesign.htmllt/linkgt lt/lea
fgt ltleafgt ltleafTextgtProduct/Document
Usedlt/leafTextgt ltlinkgt\inputProduct.htmlt/linkgt
lt/leafgt ltleafgt ltleafTextgtProduct/Document
Developedlt/leafTextgt ltlinkgt\outputProduct.htmlt/l
inkgt lt/leafgt lttreegt
The web portal contents and navigation are driven
by an XML document that implements the activity
model instances

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Process Web Site Snapshot 2

• XML document drives
• Navigation menu structure
• Page content

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Capture Lessons Learned
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Capture Lessons Learned as an XML Document

• The structure of a lesson is defined by this XML
  schema
• A Java servlet saves the submitted lesson as an
  XML document conforming to the schema
• XML stylesheets define the web page layout of a
  lesson capture form and a lesson display page

lt?xml version"1.0" ?gt - ltxsdschema
xmlnsxsd"http//www.w3.org/2001/XMLSchema"
elementFormDefault"qualified"gt - ltxsdelement
name"lesson"gt - ltxsdcomplexTypegt -
ltxsdsequencegt   ltxsdelement name"name"
type"xsdstring" /gt   ltxsdelement name"phone"
type"xsdstring" /gt   ltxsdelement name"email"
type"xsdstring" /gt   ltxsdelement name"org"
type"xsdstring" /gt   ltxsdelement
name"facility" type"xsdstring" /gt  
ltxsdelement name"project" type"xsdstring" /gt
  ltxsdelement name"activity" type"xsdstring"
/gt   ltxsdelement name"date" type"xsdstring"
/gt   ltxsdelement name"topic" type"xsdstring"
/gt   ltxsdelement name"keywords"
type"xsdstring" /gt   ltxsdelement
name"summary" type"xsdstring" /gt  
ltxsdelement name"description" type"xsdstring"
/gt   lt/xsdsequencegt   lt/xsdcomplexTypegt  
lt/xsdelementgt   lt/xsdschemagt
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Capture New Lessons

• Lesson XML schema plus stylesheet drive lesson
  capture web page
• Captured lesson is saved as an XML document
  conforming to the XML schema
• Lesson search exploits XML schema

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Next Steps for the Process Web

• Complete implementation of the model-driven web
  portal
• Including incorporation of ED14 Process Asset
  Library, software engineering standards, design
  patterns, etc.
• Apply to other engineering processes
• NASA NPG 7120.5x Program/Project Management
  Processes and Requirements
• NASA NPG 71xx.x System Engineering Processes and
  Requirements
• Implement process tailoring, instantiation, and
  enactment for a product-specific development
  project
• Integrate with model-driven semantic search (NASA
  Standards Advisor MetaMatch, etc.)
• Move closer to an ontology that supports
  reasoning
• Incorporate Process Specification Language (PSL)
  ontology
• Use Ontology Web Language (OWL) and the semantic
  web tools and inference engines it enables

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Further Possibilities for the Process Web

• Semantic-based search for activity-relevant
  standards and lessons learned
• Formal reasoning about activity specifications
  and reusable work products
• Dynamic assembly and tailoring of process
  elements from reusable process components
• Process automation
• Assurance of process conformance
• Reasoning about process usage metrics and process
  improvement opportunities
• etc.

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Conclusion

• We have prototyped an interactive, web-based
  process support tool
• Software engineering process information for a
  flight software development organization
• Link to standards, lessons learned, etc.
• We have prototyped a formal underlying model
  (ontology) of the software engineering process
• Model-driven process web
• Enables semantic-based search, process
  automation, process assembly, etc.

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For more on the NASA Standards Advisor
Project See http//cs.ua.edu/SEL/Standards_Advis
or.htm Contact Scott Hawker hawker_at_cs.ua.edu 1
205-348-1667