Disadvantages Of Formal Methods In Software Engineering In Software Engineering

Formal Methods:

Formal methods are a set of techniques that are used in software engineering for software and hardware system specification, development and testing. For this purpose these techniques employ mathematics and other formal logics. Formal methods are used in software engineering and computer science as a basis for complex systems and as methods that give out reliable and vigorous software designs. Formal methods are considered as a standard approach to software development methodology. Formal methods can take various levels of complexity from English language with little mathematical notations to fully formal language notations and rules.

The Process:

First, the requirements of the system are specified. Second, abstraction of the

• Validation: which is used for testing and checking the correctness of the system under development.

Need for Formal Methods:

Soft wares are getting complex day by day as the number of components they are comprised of are increasing day by day. Also the systems with embedded soft wares have become more complex. So in order to maintain reliability in such tangled software systems and to prove their correctness, which is very difficult, formal methods can play a vital role.

Advantages and Disadvantages of using Formal Methods:

Using formal methods provides a confidence that the system under development is correct and allow you to communicate or defend its rightness. Using formal methods gives out a better design and a good understanding of the problem domain.

But using formal methods has some draw backs like specification of the system functionality is difficult to write and to proof it is even more difficult and it could be wrong. Using it can leave out system and hardware constraints. Formal methods are not suitable for GUI systems.

Software Products using formal

• On-board receiver: which receives the message and sends it to the on-board equipment.

• On-board equipment: which can then process the signal and perform actions accordingly.

Now this is a complex system with its architecture consisting of many components. In this system formal methods can be applied on the on-board equipment which implements some algorithm to apply brakes to the train when SPAD (signal passed at danger) occurs. It can be applied on the on-board and the encoder hardware as we are using the same hardware for both. Formal methods can also be applied to address the communication protocols between the panel and signal controller and between the transponder and train.

Structured Methods:

Structured methods were originally created to support function oriented design which is very popular among soft wares. In this technique of software development high level functions are successively decomposed into more detailed functions which are then sketched to a modular design. This successive decomposition is technically known as top down approach. Structured methods are used to do high level designing. It consists of following two