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Systems Analysis

EXERCISE 1. Read the text using a dictionary if necessary. Make up a list of unknown words.

Computers are becoming our way of life and one cannot imagine life without computers in today’s world. Since computers are used in every possible field today, it becomes important to understand and build computerized systems in an effective way. Building such systems is not an easy process but requires certain skills and capabilities to understand and follow a systematic procedure towards making of any information system. For anyone who is a part of this vast and growing Information Technology industry, having basic understanding of the development process is essential.

The development of a computer-based information system includes a systems analysis phase which produces or enhances the data model which itself is a precursor to creating or enhancing a database. When a computer-based information system is developed, systems analysis would constitute the following steps:

  • The development of a feasibility study, involving determining whether a project is economically, socially, technologically and organizationally feasible.

  • Conducting fact-finding measures, designed to ascertain the requirements of the system's end-users. These typically span interviews, questionnaires, or visual observations of work on the existing system.

  • Gauging how the end-users would operate the system (in terms of general experience in using computer hardware or software), what the system would be used for etc.

It is often useful (or necessary) to break up a system into smaller pieces for analysis. A system is characterized by how it responds to input signals. In general, a system has one or more input signals and one or more output signals. Therefore, one natural characterization of systems is by how many inputs and outputs they have. Signals can be continuous or discrete in time, as well as continuous or discrete in the values they take at any given time. Signals that are continuous in time and continuous in value are known as analog signals. Signals that are discrete in time and discrete in value are known as digital signals. Signals that are discrete in time and continuous in value are called discrete-time signals. With this categorization of signals, a system can then be characterized as to which type of signals it deals with. A system that has analog input and analog output is known as an analog system. A system that has digital input and digital output is known as a digital system.

Another way to characterize systems is by whether their output at any given time depends only on the input at that time or perhaps on the input at some time in the past (or in the future!). Memoryless systems do not depend on any past input. Systems with memory do depend on past input. Causal systems do not depend on any future input. Non-causal or anticipatory systems do depend on future input.

Finally, systems may be characterized by certain properties which facilitate their analysis. A system is linear if it has the superposition and scaling properties. A system that is not linear is non-linear. If the output of a system does not depend explicitly on time, the system is said to be time-invariant; otherwise it is time-variant. A system that will always produce the same output for a given input is said to be deterministic. A system that will produce different outputs for a given input is said to be stochastic.

For conducting a systematic procedure towards making of any information system, experts in the field have devised various methodologies. Waterfall model is one of the oldest methodologies. Later Prototype Model, Object Oriented Model, Dynamic Systems Development Model, and many other models became very popular for system development. For the students aspiring to become professionals in the field a thorough knowledge of these basic system development methodologies is very important.

EXERCISE 2. Give Russian equivalents for the following English words and word combinations:

systematic procedure, to create a database, to operate the system, hardware, software, output signal, memoryless systems, facilitate analysis, non-linear system, to devise methodologies.

EXERCISE 3. Give English equivalents for the following Russian words and word combinations:

Навыки и способности, информационная система, конечный пользователь, цифровой сигнал, определенные свойства, глубокие знания, модель развития динамических систем.

EXERCISE 4. Define the part of speech and the functions of all V-ing forms in the text. Translate them into Russian.

EXERCISE 5. Match up the words in column A with the words in column B to form meaningful phrases.

A B

1. computerized a. observation

2. information b. properties

3. visual c. development

4. input d. technology

5. scaling e. system

6. system f. Signal

EXERCISE 6. Find all the adjectives describing the word “system” and define the made-up notions.

EXERCISE 7. Fill in the gaps with the following prepositions:

With on in without of for

  1. It is impossible to live in a modern world … computers.

  2. Analog signals are those which are continuous … time and value.

  3. Digital system deals … digital input and digital output.

  4. Time-variant system depends … time.

  5. It is very important … a student to acquire knowledge in system development methodologies.

  6. Object Oriented Model is one … the modern methodologies used in Systems Analysis.

EXERCISE 8. Answer the following questions.

  1. What is important for a specialist of Information Technology industry?

  2. What is the aim of a systems analysis phase?

  3. What are the steps of systems analysis?

  4. What kind of signals is a system characterized?

  5. What system is called linear?

  6. What are the methodologies of systems analysis?

  7. Why is it important for a student to know basic system development methodologies?

EXERCISE 9. Write out of the text all international words. Why do you think these words are international?

EXERCISE 10. Surf the Internet for some information on any methodology for system development and prepare a presentation for your groupmates.

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