Differentiate system development tools
Modelling
Prototyping
Computer-Aided Systems Engineering (CASE)
Modeling produces a graphical representation of a concept or process that systems developers can analyze, test, and modify.
A systems analyst can describe and simplify an information system by using a set of business, data, object, network, and process models.
Prototyping tests system concepts and provides an opportunity to examine input, output, and user interfaces before final decisions are made.
Definition: A prototype is an early working version of an Information system.
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Computer-aided software engineering (CASE) is the domain of software tools used to design and implement applications. ... CASE software is often associated with methods for the development of information systems together with automated tools that can be used in the software development process.
case tools features
There are 3 model. Business, Object and Process model. All these models help in the information system understanding System developers often use tools which is Visio to display information related to business. Visio is a popular tool that systems analysts can use to create business process diagrams, flowcharts, organization chart, network diagrams, floor plan, project timelines, and work flow diagram.
Prototype Purpose:
To tests system concepts and provides an opportunity to examine input, output, and user interfaces before final decisions are made.
A prototype is an early working version of an information system.
Just as an aircraft manufacturer test a new design in a wind tunnel, systems analysts construct and study information systems prototypes.
Checks for syntactic correctness
Data dictionary support
Checks for consistency and completeness
Navigation to linked diagrams
Layering
Requirements traceability
Automatic report generation
System simulation
Performance analysis
Advantage:
A prototype can serve as an initial model that is used as benchmark to evaluate the finished system, or the prototype itself can develop into the final version of the system.
types of case tools
Either way, prototyping speeds up the development process significantly.
LOWER CASE
support coding phase
Disadvantage:
INTEGRATED CASE
also known as I-CASE support analysis, design and coding phases
Important decisions might be made too early, before business or IT issues are understood thoroughly.
UPPER CASE
support analysis and design phases
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A business model/ requirements model, describes the information that a system must provide.
A data model describes data structure and design.
An object model describes objects, which combine data and processes.
A network model describes the design and protocols of telecommunications links.
A process model describes the logic that programmers use to write code modules.
MAJOR CASE RISK FACTOR
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Inadequate process control. CASE provides significant new capabilities to utilize new types of tools in innovative ways. Without the proper process guidance and controls these new capabilities can cause significant new problems as well
Inadequate training. As with any new technology, CASE requires time to train people in how to use the tools and to get up to speed with them. CASE projects can fail if practitioners are not given adequate time for training or if the first project attempted with the new technology is itself highly mission critical and fraught with risk.
Unrealistic expectations. The proponents of CASE technology—especially vendors marketing expensive tool sets—often hype expectations that the new approach will be a silver bullet that solves all problems. In reality no such technology can do that and if organizations approach CASE with unrealistic expectations they will inevitably be disappointed.
Inadequate standardization. Organizations usually have to tailor and adopt methodologies and tools to their specific requirements. Doing so may require significant effort to integrate both
divergent technologies as well as divergent methods. For example, before the adoption of the UML standard the diagram conventions and methods for designing object-oriented
models were vastly different among followers of Jacobsen, Booch, and Rumbaugh.
A prototype based on careful fact finding and modelling techniques, however can be an extremely valuable loot.