Software Design

1. Automated graphics facilities for producing charts and diagrams in support of modeling activities
2. Screen and report generators to assist in designing the dialogue/presentation of the proposed information systems
3. Data dictionaries providing a central repository for all definitions used by the development team
4. Reporting facilities ranging from project management statistics through to design inconsistencies
5. Analysis and cross-referencing tools to ensure integration of model views
6. Code generators and documentation generators utilising the deliverables of the modeling activities to develop working systems

1.      Enforcing a standard development methodology and design principle

2.      Providing a central repository for all design components and making them available to all the design team

3.      By improving communications between the designers and end-users using graphical representations of the system design

4.      Automating tedious and error-prone analysis and design activities thus proving consistency between views

5.      By automating code generation (to a certain degree), testing and version/change control activities

Upper CASE tool

Modeling Features, Analysis tools, Cross referencing tools, Central Repository, Documenetation generators

 Logical

I-CASE tool

Modeling Features, Analysis tools, Cross referencing tools, Code generators, Testing, Screen/Report generators, Central Repository, Documentation generators

Lower CASE tool

Code generators, Testing Screen/Report generators, Central Repository, Documentation generators

Physical

·         Language compiler

·         Structured editor: to create and edit source programs

·         Linker: to link object code components

·         Loader: to load an executable program into the computer memory

·         Cross-referencer: to produce a cross-reference listings of source programs

·         Static analyzer: to analyze source programs in order to find anomalies

·         Dynamic analyzer: to analyze how many times each statement of a source program has been executed when the program was run

·         Interactive degugger: to trace and control the execution of user program

·         Diagramming editors: Are used to create DFDs, ERDS charts etc. The editor is not just a drawing tool but understands the meaning of different symbols/objects. It captures information about these objects and saves this information in a central repository.

·         Checking facilities: Are used to ensure that models created by analysts/designers are internally consistent and complete and all models are consistent with one another (externally consistent)

·         Query language facilities: Is used to browse the repository and examine completed designs

·         Data dictionary facilities: Are used to maintain information about the objects used in various diagrams

·         Report generation facilities: Are used to automatically generate system documentation

·         Form generation tools: Are used to specify screen and document formats

·         Skeleton code generators: Are used to generate code or code segments automatically from the design stored in the central repository

·         Import/Export facilities: Allow the interchange of information with other development tools

·         Test manager: to record testing

·         Test data generator: to generate test cases

·         Oracle: to generate predictions of expected results

·         File comparators: to compare results of program test

·         Report generator: to automatically generate system documentation

·         Dynamic analyzer: to analyze how many times each statement of a source program has been executed when the program was run. It is useful to produce an execution profile of the tested program to achieve the proper coverage for white box testing

·         Simulator: to simulate an environment (Eg; hardware, users) for tested programs. Simulators are very useful when testing real-time systems

1.

Project Management and control is improved: CASE tools can aid the project management and control aspects of a development environment. Some CASE tools allow for integration with industry-standard project management methods (such as PRINCE). Others incorporate project management tools such as PERT charts and critical path analysis. By its very nature, a CASE tool provides the vehicle for managing more effectively the development activities of a project.

2.

System Quality is improved: CASE tools promote standards within a development environment. The use of graphical tools to specify the requirements of a system can also help remove the ambiguities that often lead to poorly defined systems. Therefore, if used correctly, a CASE tool can help improve the quality of the specification, the subsequent design and the eventual working system.

3.

Consistency checking is automated: Large amounts of information about a business area and its requirement are gathered during the analysis phase of an information systems development project. Using a manual system to record and cross reference this information is both time-consuming and inefficient. One of the advantages of using CASE tool is that all data definitions and other relevant information can be stored in a central repository that can then be used to cross check the consistency of the different views being modelled.

4.

Productivity is increased: One of the most obvious benefits of a CASE tool is that it may increase the productivity of the analysis team. If used properly, the CASE tool will provide a support environment enabling analysts to share information and resources, manage the project effectively and produce supporting documentation quickly.

5.

The maintenance effort is better supported: It has been argued that CASE tools help reduce the maintenance effort required to support the system once it is operational. CASE tools can be used to provide comprehensive and up-to-date documentation – this is obviously a critical requirement for any maintenance effort. CASE tools should result in better systems being developed in the first place.

1.

Need for organization - wide commitment: To be used effectively, CASE tools require the commitment of the organisation. Every member of the development team must adhere to the standards, rules and procedures laid down by the CASE  tool environment.

2.

Unrealistic expectations: CSE tools cannot replace experienced business/systems analysts and designers. They cannot automatically design a system nor can they ensure that the business requirements are met. Analysts and designers still need to understand the business environment and identify the system requirements. CASE tools can only support the analytical skills of the developers, not replace them.

3.

Long learning curve: CASE is technical software. It will take time for the development team to get use to flow and use it effectively for development work.

4.

Costs of CASE tools: CASE tools are complicated software packages and are, therefore, expensive to buy. In addition to the initial costs, there are many ‘soft’ costs that have to be considered. These ‘soft costs’ include integration of the new tool, customising the new tool, initial and on-going training of staff, hardware costs and consultancy provided by the CASE tool vendor.