System Structure Analysis
Objectives
System structure analysis provides a way for analysts to see how various
process action diagrams created in business rule analysis interrelate. This task
may be applied prior to or concurrently with business rule analysis. The
structure chart is a system level view of how various process diagrams
interrelate. One process may, for example, be invoked by another process.
This chart also identifies uses of common routines accessed by multiple
processes across an application. From the perspective of an existing system,
this task allows an analyst to diagram how current modules interrelate.
This analysis may be used to re-document current systems and as input to
redevelopment projects. In the second case, this task supports target
specification of process logic by allowing analysts to compare and contrast how
current processes interrelate.
Specific objectives include:
· Documenting current system process relationships by deriving
structure charts from current systems
· Establishing new structure charts for target applications
Entrance Criteria
The entrance criteria for the system structure analysis are listed below.
· Completion of the functional assessment, function hierarchy analysis
· Completion of the functional assessment, function dependency
analysis
· Completion of process hierarchy/dependency analysis for
current/target systems - as dictated by scenario
· Completion of logical data analysis task - as dictated by the
invoking scenario
· Completion of system flow (DFD) diagrams created during general
system architecture assessment for each system being analyzed
Note: Business rule analysis is optional based on re-documentation versus
redevelopment objectives and development methodology directives.
· Completed process action diagram(s) for current/target systems
Roles/Skills
The personnel and skill requirements necessary to meet the system structure
analysis task objectives are identified below.
· Redevelopment Expert
- Ability to determine best mix of top-down/bottom-up analysis and
how to integrate these techniques
· Function Modeling Expert
- Expertise in capturing and merging bottom-up system structure
charts & integrating those charts into related bottom-up and/or
top-down models
· Current Systems Expert
- Knowledge of existing system source environment
- Knowledge of the functionality of current system
· Target System Functional Expert
- Knowledge of target functional requirements
Input Requirements
The system components and related inputs required to initiate and complete
the system structure analysis task are listed below.
· Current function hierarchy diagrams for each system entering this
task
· Current function dependency diagrams for each system entering this
task
· Completed Functional assessment Form 005 for each system entering
this task
· Current process hierarchy and dependency diagrams for each system
entering this task
· If applicable, integrated target process hierarchy and dependency
diagrams created in process hierarchy/dependency analysis task - scenario
driven
· Completed/updated Functional mapping Form 004 for each system
entering this task
· Completed Transformation process mapping Form 031 - corresponding to
each system process hierarchy input above
· Completed mapping Forms 004 and 031, if applicable, for integrated
target system hierarchy created in process hierarchy/dependency analysis
task
· Existing system components - all source code for all current systems
entering this task is required
· Completed logical (normalized) data model as defined in logical data
analysis task
· Completed process action diagrams as defined in business analysis
task
Note: Top-down inputs depend on scenario driving task.
· Top-down function and process hierarchy diagrams (if required by the
scenario driving this process)
· Top-down function and process dependency diagrams (if required by the
scenario driving this process)
Tool/Technology Support
Technologies supporting the system structure analysis task include I-CASE
modeling and analysis import facility tools. These tools are used to represent
information as required by this task.
I-CASE Modeling Tools
Technology support for this step requires the I-CASE tool set that was
applied in prior tasks of the Transformation stage. Features include:
· Analysis workstation: ability to specify bottom-up and top-down
system structure charts in diagramming tool
· Analysis workstation: ability to utilize process model data loaded,
by prior steps, into integrated tool encyclopedia
Analysis Import Facility
This tool facilitates representation of current systems structural flows in
structure chart format. While representation may be derived from physical
implementation, it could provide a working starting point for an analyst.
Features include:
· Imports multiple physical objects into analysis workstation
· Imports current system structure chart representation into analysis
workstation
Task Steps
The system structure analysis task is comprised of the following task steps: