Use of XML for Product Data Exchange Henson Graves, Chris Johnson, Tom Teigen, Abbie Ghose Lockheed

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Use of XML for Product Data ExchangeHenson
Graves, Chris Johnson, Tom Teigen, Abbie
GhoseLockheed Martin Aeronautics Company, Joint
Strike Fighter ProgramRoy ScrudderApplied
Research LaboratoriesThe University of Texas at
AustinJames W. HollenbachSimulation
Strategies, IncSteve HixParadigm Technologies,
Inc.

• Approved for Public Release AER200403010

Ref
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Content

• Product data has broad scope, is stored in
  multiple places and has overlap dependencies
  (charts 3-4)
• Storage number of tools adds to complexity
• Managing metadata is critical to assuring a
  coherent product model
• JSF approach is to build a product development
  information model (charts 5-9)
• Represents organization structures and classes of
  data
• Includes metadata needed to understand data
  assess integrity
• Provides traceability of data (lineage, pedigree)
• We have formalized an information metamodel in
  XML (charts 10-14)
• Metamodel is a specification for information
  models
• XML schemas are used to describe data content
• XML enables checking for data interoperability
  integrity assessment
• Is the approach really practical? (chart 15)
• Implemented metamodel, issues of capturing
  metadata process info
• Where we go from here (chart 16)
• Validation roadmap

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Product Data Has Broad Scope, is Stored in
Multiple Places and Has Overlap Dependences
Product Data to be Managed

• concurrent work on all lifecycle activities
• 500 tools with few common formats
• 30 persistent data storage systems
• A terabyte of data growing to 100s of terabytes

PDM Tool
represents data dependences
4
Managing Metadata (data about data) is Critical
to Assuring a Coherent Product Model

• What is the authoritative source?
• Overlapping data is available from multiple
  sources
• Requires rules to identify the authoritative
  source
• How is the data produced?
• What processes and tools were used to produce the
  data
• What assumptions went into its derivation
• Requires documentation on data linage
• Can applicability be determined?
• Difficult to determine applicability of data to
  product variants
• Requires tagging data with applicability
  conditions
• Who is responsible for providing missing data?
• Program requirements often fail to include
  requirements for exporting information and plans
  for managing data

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JSF Technical Approach is to Build a Product
Development Information Model
... and use it via a web-based access system for
data access and traceability
Information Model (info organization,
interrelationships, metadata data locations
DOORS
SIMS
Other databases
PVCS
Resource Access System
JDL
Web Browser (RAS GUI)
Metaphase
Application server
Database repositories
6
Information Model Provides an Organizational
Structure and Classes of Data
... used for location access

• Catalogs
• Product decomposition
• Work organization
• Processes

Views for catalog component
Navigation of catalog
7
The Information Model Defines Metadata Required
for Integrity Assessment
... and Web-access provides data registration
forms for data input
8
Data Content in XML can be displayed and searched
9
The Information Model Uses Process Models to
Check for Data Consistency Coherency
Input data type with constraints

• The baseline process
• Identifies the significant parameters
• Identifies places where the same data is used
• Provides a template for constraints
• Describes how constraints propagate

Method of calculating result
Constraints
10
We Have Formalized a Metamodel For Product
Development Information Models

• Specification for creating information models
• A standard for data integrity assessment
• XML representation enables data interoperability
  between systems

The diagram above is a part of a UML class model
for the metamodel generated from XML schemas
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The Information Metamodel is Implemented Using
XML schemas for the entity classes
Information Resource Schema
ltxsdelement name"parameterGroup"gt
ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement ref"sourceRef" minOccurs"0"/gt
ltxsdchoice minOccurs"0" maxOccurs"unbounded"
gt ltxsdelement ref"parameterGroup"/gt
ltxsdelement ref"array"/gt
ltxsdelement ref"parameter"/gt
ltxsdelement ref"text"/gt lt/xsdchoicegt
lt/xsdsequencegt ltxsdattribute
name"name" use"required" type"xsdstring"/gt
ltxsdattribute name"dataType"
type"xsdstring"/gt lt/xsdcomplexTypegt lt/xsdele
mentgt
Product Decomposition in XML
ltitem name"JSF Air System" class"WBS"
tier"1"gt ltitem name"Air Vehicle" class"WBS"
tier"2"gt ltitem name"Mission Systems"
class"WBS" tier"3"gt ltitem name"Tactical
Information Systems" class"WBS" tier"4"gt
ltitem name"Electro Optics Systems" class"WBS"
tier"5"/gt ltitem name"Communication and
Navigation Integration" class"WBS" tier"5"/gt
ltitem name"Radar" class"WBS" 35"
tier"5"/gt ltitem name"Electronic Warfare
and Counter Measures" class"WBS" tier"5"/gt
lt/itemgt ltitem name"Integrated Core
Processor" class"WBS" tier"4"gt ltitem
name"Core Processing Domain Software"
class"WBS" tier"5"/gt ltitem name"ICP
Hardware" class"WBS" tier"5"/gt ltitem
name"Common Components" class"WBS" tier"5"/gt
lt/itemgt lt/itemgt lt/itemgt lt/itemgt
Information Resource in XML
ltparameterGroup name"BWL_AC_PERF"
dataType"BWL_AC_PERF"gt ltsourceRefgtHand
Datalt/sourceRefgt ltparameter
dataType"arotyp" name"arotyp"gt
ltunitsgt ltunitgtunitlesslt/unitgt
lt/unitsgt ltdataFormatgt
ltinteger/gt lt/dataFormatgt
ltvaluegt1lt/valuegt lt/parametergt
ltparameter dataType"pst_cap" name"pst_cap"gt
ltunitsgt ltunitgtunitlesslt/unitgt
lt/unitsgt ltdataFormatgt
ltlogical/gt lt/dataFormatgt
ltvaluegtFlt/valuegt lt/parametergt
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We Use Commercial Standards For Data Content
Where Feasible, But Developed Our Own Schemas For
Metadata

• Many additional schemas are under consideration
• The list will expand and change over time
• For the time being much data will be opaque,
  i.e., in tool specific format

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XML Graphic For Schema Representing Information
Resource Class
14
The Metamodel is represented as a collection of
XML Schemas
... which enable mechanical checking of metamodel
standard compliance

• XML schemas can be used to describe metadata and
  representations of common design language
  formats, e.g., UML, X3D,
• XML processors perform validation of data for
  standard compliance, constraint checking, and
  consistency
• XML transformation rules can be used to
  transform data to produce specific presentation
  and tool formats

XML Schemas For Metamodel
Transformation Rules for Generating Output Format
s
XMLdoc
doc
XML Agent
Storage
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Is The Information Model Approach Really
Practical?

• We have implemented an application server, called
  the Resource Access System (RAS), that is
  configured with the information model
• Use Web-services to connect to legacy databases
• Some issues with connection to legacy systems
• Issues with capturing metadata
• Provide good interface, automate info collection
  as much as is possible
• Get policy directives that require metadata
  input, use management boards as forum to capture
  metadata
• Issues with capturing info about processes that
  produce data
• Requires work
• Must convince management that task is worth cost

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Where We Go From Here

• First large scale deployment of Metadata
  implementation is in progress
• Will find out how well the metadata approach
  works
• Expect to use technical management boards to
  authenticate data and metadata
• Will find out how feasible this is
• Continue analysis of baseline processes to better
  understand how constraints are propagated
• Determine the technical feasibility of capturing
  process elements
• Continue to refine the schema list that describe
  for data content
• e.g,. STEP, PLM XML, .
• The ability to validate integrity of data
  requires cultural change