The objectives of the general system architecture assessment are identified below.
· Summarize and document current architectural design
· Document high-level information flow for the application
· Assess related system interfaces and nature of those interfaces
· Identify and document nature and impact of all non-standard technologies
The entrance criteria for the general system architecture assessment are listed below.
· Completion of objective setting/proposal development task
· Completion of environmental analysis task - particularly creation of system component cross reference analysis
· Access to the existing application environment
Note: The following is an optional, top-down activity completed outside the scope of an Inventory/Analysis assessment.
· Identification of target technical and data architecture by strategic planning team
Optional - where available
· Population of LTM model as completed in entrance criteria tasks
· Completion of Enterprise Redevelopment Planning, data architecture assessment task identifying shared data stores
The personnel and skill requirements necessary to meet the general system architecture assessment task objectives are identified below.
· Redevelopment Expert
- Experience and ability to apply system-wide or multi-system-wide architecture analysis techniques
- Basic repository update skills
· Current Systems Expert
- Knowledge of program interfaces and data flows
· Data Flow Diagramming Expert
- Expert at developing a DFD
· Metric Analyst
- Ability to assess & record architectural metrics
The system components and related inputs required to initiate and complete the general system architecture assessment are listed below.
· Existing physical system components
Note: Primary inputs were captured during environmental analysis. System is required to refresh this data or if an automated DFD generation tool is available.
· The following object cross reference reports produced during environmental analysis task:
- JCL, Proc, Step to Executable Program
- Executable Program, DD Name to Physical File/Database
- Executable on-line Program to Screen Macro Definition
- Executable Module to Source Module(s)
- Copy to Program(s) and Program to Copy(ies)
- Calling Program to subordinate Called Program(s)
- Called Program to Calling Program(s)
- File/Database to Executable Program(s)
- Executable Program to File(s)/Database(s)
- Screen to Program(s)
- Program to Screen(s)
· Completed Inventory/Analysis Executive Planning Form 001 and Environmental Analysis Form 003A
· A blank copy of the Architectural Assessment Form 006
Optional for systems not requiring a change in architecture.
· Target architecture based on strategic redevelopment objectives
Optional - where available.
· Legacy transition meta-model (LTM) populated with all system components and relationships based on use in prior Comsys-TIM tasks
· Business Area/Data Store Matrix Form 041 defining major data stores that cross functional business area boundaries
Tools supporting this task are used to document internal system flows as well as links to interface systems outside the scope of this assessment. System level flow analysis is supported by system cross reference analyses created during the environmental analysis task.
The tool(s) used during environmental analysis should be available throughout the architectural analysis to refresh system-wide meta-data as needed, or to produce additional reports as identified in task steps below. Specific tool requirements for this task are described in the following paragraphs.
Data flow diagramming tool
The data flow diagramming (DFD) tool is used to document current system information flows. This may be done manually or with a drawing tool, but DFD tools allow models to be modified easily.
· Chart system flows at the program /file level
· Chart information flows to/from interface systems
Environmental analyzer
· Generate Job/program/data set flow diagrams within IBM MVS environments - optional
· Optionally, automatically generate data flow diagrams from JCL for IBM MVS batch environments
Note: If automated analysis tools are available (see step level tool guidelines), it can significantly reduce time required to document batch system flows using a DFD.
· Underlying repository of physical objects linked according to naturally occurring relationships - optional but highly recommended feature for this task if no LTM repository available
· Call structure invocation diagramming facility
Spreadsheet
This tool is used to record metric results for this task.
Open systems repository
A repository provides an important, yet optional, capability to link business areas, systems and components using the legacy transition meta-model. In this task, the repository is used to trace relationships between data stores and executables as input to the diagramming process. It is also updated to reflect or refine system to system and system to sub-system relationships.
Word processor
This is required to record analysis results.
The general system architecture assessment task is comprised of the following task steps:
