Composition of information systems. Information system. IP classification. Structural components of corporate IP Main components of IP
Definition of information system (IS). IS tasks and functions
IP - an interconnected set of means, methods and personnel used to collect, store, process and issue information in order to achieve a given goal. Computers equipped with specialized software, serve as a technical basis and tool for information systems.
In other words under IP is understood as an organizationally ordered collection of documents (arrays of documents) and information technologies, including using funds computer technology and communications that implement information processes.
IS tasks and functions
With organizational isolation, information systems solve two groups of problems:
1. task group information support :
· selection of necessary messages and their processing,
· storage,
· search and provision of information to the subject of the main activity. (With a predetermined completeness, accuracy and efficiency in the most acceptable form for data processing systems).
2. a group of tasks related to processing received information in accordance with certain algorithms or programs in order to prepare solutions to the problems facing the subject of the main activity (the so-called “ custom ” tasks).
To solve such problems IP must have necessary information O subject area (BY) the subject of the main activity, the problems facing it, must be able to use existing models for solving problems using data processing tools or independently build such models, and also have a certain artificial or natural intelligence.
Preliminary definition. Subject area – this is a set of objects and relationships between them, limited by the needs of a specific subject of the main activity.
More detailed concept « Subject area" discussed in paragraph 5 of this lecture .
To solve the assigned tasks, the IS must perform the following main functions:
· selection of messages from the internal and external environment necessary for the implementation of the main activity;
· entering information V IP;
· storing information in memory, updating it and maintaining integrity ;
· processing, searching and issuing information in accordance with the requirements specified by the subject of the main activity. ( Treatment may include preparation of solution options user applied tasks using appropriate algorithms (programs)).
Composition and structure of the IP, main elements, order of operation
IP structure is an interconnected collection of its parts, called supporting subsystems.
Subsystem - This is a part of the system, distinguished by some characteristic.
Main supporting subsystems
· Information Support,
· technical support,
· software,
· software,
· organizational support,
· legal support.
Basic elements, order of operation of the IS.
The main processes of information transformation are the following processes:
collection of information;
acquisition of information;
search and display of information for system subscribers;
maintaining the integrity, relevance and safety of information .
These processes ensure the work IP for any purpose, can be roughly represented in the form of a diagram consisting of blocks:
· input of information from external or internal sources;
· processing input information and presenting it in a convenient form;
· output of information for presentation to consumers or transfer to another system;
· Feedback- this is information processed by people of a given organization to correct input information.
Therefore, to implement the IS functions indicated above, three independent functional subsystems are distinguished:
1. Organizational and technological subsystem for collecting information ensures the selection and accumulation of data into the information system and includes a set of information sources, organizational and technological chains for selecting information for accumulation in the system. Without a properly organized, promptly and effectively operating organizational and technological subsystem for collecting information, it is impossible to effectively organize the functioning of the entire IP generally.
IP can process (process) only the information that is entered into it. At the same time, the quality of work IP determined not only by its ability to find and process necessary information in its own array and provide it to the user, but also the ability to select relevant information from the external environment.
This selection is carried out this subsystem, which accumulates data about the information needs of users IP(internal and external), analyzes and organizes this data, forming information profile IP. The information selection algorithm transforms input streams into information array IP.
2. Subsystem for presentation and processing of information forms the core IP and is a reflection of the system’s developers and subscribers’ understanding of the structure and picture of the subject area, information about which should be reflected IS.
The subsystem for presenting and processing information is one of the most complex components in development IP.
This subsystem transforms input information and requests, organizes their storage and processing in order to satisfy the subscriber’s information needs IP.
The implementation of the functions of this subsystem requires the presence of:
· information description apparatus , namely information retrieval language, coding systems and data description language;
· organizing and maintaining information (logical and physical organization, procedures for maintaining and protecting information, etc.);
· information processing and processing apparatus (algorithms, models, etc.).
All three of these components are determined by two parameters IS: nature of information processing and functions IP.
3. Regulatory and functional subsystem for preparing and issuing information defines users, or otherwise subscribers , systems.
This subsystem directly implements the satisfaction of information needs, both internal and external users IP. To accomplish this task, the subsystem studies and analyzes information needs, determines the forms and methods of satisfying them, the optimal composition and structure of output information products, and organizes the process of information support and support.
To perform these functions you need:
· apparatus for describing and analyzing information needs and their expressions in language IP;
· apparatus of direct information support (procedures for searching and retrieving information, languages for data manipulation, etc.).
If the functions of this subsystem are identical, IP different types they differ significantly from each other. This is especially noticeable when comparing documentary And factual IP, which will be discussed in detail later.
(internal carrier of knowledge about the subject area) is database (DB). The concept of a database is central to the field of automated information systems technology.
Definition 1Database is a collection of data organized according to certain rules, providing general principles description, storage and manipulation of data, independent of application programs.
Definition 2. (GOST): A database management system (DBMS) is a set of programs and language tools designed to manage data in a database, maintain the database and ensure its interaction with application programs.
Information core of the IS information presentation and processing subsystem the highest level is database (BND), or automated data bank (DBA) – a set of the following components :
· DB,
· DBMS,
· application components IP(a set of input and output forms, standard queries for solving information technology problems in a specific subject area),
· complex technical means , on which they are implemented.
IP classification
1. By purpose:
· reference IP,
· information support systems ,
· reference and information systems , having an independent purpose.
2. By number of users and territorial basis
· single-user (For example, IP, using as BY application Excel ),
· multi-user low level (For example, IP built on the application Access ),
· multi-user high level - IP enterprise level ( distributed, very large, extra large ) .
3. By efficiency of information processing
· real time system
· system for operational processing of transactions,
· batch processing system .
4. By functional characteristics and management levels
· production systems;
· marketing systems;
· financial and accounting systems;
· personnel systems (human resources);
5. By degree of automation
· manual,
· automatic,
· automated .
6. By the nature of information use
· information retrieval systems,
· information decision systems :
o managers IP,
o advising IP.
7. By area of application
· IP organizational management ,
· IP process management (TP),
· IP computer-aided design (CAD),
· Integrated (corporate) IP,
· Computing IS.
8. According to the composition of the processed information, imposing strict requirements on the apparatus for its description, organization and search
· documentary IP(poorly structured information);
· factual IP(rigidly structured information);
· documentary and factual IP.
· geographic information systems.
9. By scale
· worldwide,
· international,
· republican,
· regional,
· industry,
· associations,
· enterprises and divisions.
MINISTRY OF EDUCATION AND SCIENCE OF RUSSIA
FSBEI HE "URAL STATE FORESTRY UNIVERSITY"
Faculty of Secondary Vocational Education
N.V. Kharlova
INFORMATION TECHNOLOGY IN PROFESSIONAL ACTIVITIES
Guidelines and test assignments for part-time students studying in the specialty 02.23.03 “ Maintenance and repair of motor vehicles"
Reviewer - Busygina N.A., teacher of computer science and information technology, highest category
Educational Toolkit compiled taking into account the requirements of the federal state educational standard of secondary vocational education.
Target– provide assistance to distance learning students in organizing their independent work on studying the material.
INTRODUCTION
Currently, information technologies are used in all spheres of human activity. The effective use of information technologies is largely determined by the level of qualifications of specialists who create and use these technologies in their practical activities.
The purpose of studying the discipline- to develop in students the knowledge and ability to use software for effective information processing various types when solving professional problems.
As a result of studying the discipline, the student must:
Have an idea:
About the objectives of the academic discipline,
About the components of information systems,
Know:
Information technology software and its capabilities,
Technical support of information technologies and its capabilities.
Be able to:
Use the capabilities of software and hardware in professional activity.
The academic discipline “Information technologies in professional activities” is related to the content practical classes disciplines of specialty: “Car design”, “Rules and road safety”, “Road transportation”.
The main form of studying course material by students is independent work above the recommended literature. During the session, during review classes, the material being studied is systematized, generalized, and the most complex issues are addressed. Further, the studied material is consolidated during practical classes, which are provided for in the work program of the discipline.
Students begin studying the discipline “Information Technologies in Professional Activities” by studying the literature recommended at the orientation lesson by the teacher. To systematize the material being studied, it is necessary to take notes on the topics specified by the teacher. The compiled outline will allow you to quickly navigate the material necessary to complete the task. practical work, home test and will make it easier to prepare for the test.
Before execution home test(DKR) students need to familiarize themselves with the content work program disciplines, work through theoretical material, check the availability of the necessary computer program to complete tasks.
When performing DKR, the following requirements must be observed:
1. DKR is completed according to the options and submitted to the teacher for verification. The option number must match the last digit of the personal file number. Work completed using any other option will not be counted.
2. The tasks of the DKR are submitted for verification in in electronic format, on any available storage medium, according to e-mail and in printed form. on A4 sheets.
3. DKR for printing is performed in text editor. On title page a certain form (Appendix 1), indicate the last name, first name, patronymic, name of the discipline, test work number, option number
4. The printed document must contain:
Questions on the studied topics of the discipline “Information technologies in professional activities”, and answers to the questions of the option,
Conditions of the tasks,
Tables with initial data and calculation results,
Under the tables, provide an explanation of the calculations performed and display the calculation formulas.
At the end of the work, sign and give a list of the literature used, indicating the initials and surname of the author, the title of the textbook and the year of publication.
5. Only DKR tasks completed in spreadsheets are submitted electronically. Problem solving is carried out in accordance with methodological instructions.
6. After receiving the checked work, you must follow all the instructions of the teacher, correct errors, make additions to the texts of the answers, and prepare the test for the session.
Final control form in this discipline is test.
DISCIPLINE WORK PROGRAM
Section 1. Information systems. Classification. Components of information systems.
The concept of “modern information technologies”. The main goals of information technology. The concept of "information system". Information system as an environment for the functioning of information technologies. Classification of information systems. Concept of automated workstation. Components of information systems (Software, information and technical). Kinds software.
Questions for self-control
1. What is information technology?
2. Components of information technology?
3. Types of modern information technologies?
4. The main purpose of information systems?
5. The main tasks of information systems?
6. List the types of software, give examples.
1.2.1 Concept and properties of the system
1.2.2 Concept and types of information systems
1.2.3. Structure and composition of the information system
1.2.4. Data processing system components
1.2.5. Organizational components of an information system
1.2.6. Information systems development trends
Literature: 4, p. 12–25; 5, p. 16–32; 7, p. 9–32.
1.2.1 Concept and properties of the system. System is any object that, on the one hand, is considered as a single whole, and on the other, as a set of interconnected or interacting components.
The term “system” is used mainly in two senses:
A system is a property consisting of a rational combination and ordering of all elements of a certain volume in time and space so that each of them contributes to the success of the activity of the entire object. Associated with this interpretation is an understanding of the coordination and synchronization of the actions of management personnel united in order to achieve their goals;
A system as an object that has a fairly complex, ordered internal structure (for example, a production process).
The concept of a system covers a complex of interconnected elements acting as a single whole. The system includes the following Components :
System structure– many elements of the system and the relationships between them. Example: organizational and production structure of an enterprise. The mathematical model of the structure is a graph.
Functions of each system element. Example: management functions - decision-making by a certain structural unit of the enterprise.
Input and output of each element of the system as a whole. Example: material or information flows entering or exiting a system. Each input stream is characterized by a set of parameters (x(i)); the values of these parameters for all input streams form a vector function X. In the simplest case, X depends only on time t, and in practically important cases, the value of X at time t+1 depends on X(t) and t. The output function of system Y is defined similarly.
Law of system behavior - function linking changes in system input and output Y = F(X).
Goals and limitations of the system and its individual elements. Example: achieving maximum profit, financial constraints.
The quality of system functioning is described by a number of variables u1, u2,..., uN. Some of these variables (usually just one variable) must be maintained at an extreme value, for example, max ul. The function ul = f(X,Y,t,...) is called target function, or purpose. Often f does not have an analytical or explicit expression at all. Remaining variables can be subject to (generally two-way) restrictions
aK<= gK(uK) <= bК, где2 <= К <=N.
Among the famous properties of systems It is advisable to consider the following: relativity, divisibility and integrity.
Property of relativity establishes that the composition of elements, relationships, inputs, outputs, goals and limitations depends on the goals of the researcher.
Divisibility means that the system can be represented as consisting of relatively independent parts - subsystems, each of which can be considered as a system.
Integrity property indicates the consistency of the purpose of the functioning of the entire system with the purposes of the functioning of its subsystems and elements.
A system, as a rule, has more properties than its constituent elements (Aristotle).
1.2.2 Concept and types of information systems. In connection with the use of new information technology based on the use of communications and computers, the concept of “ Information system "(IS).
Information system is a communication system for collecting, transmitting, and processing information about an object, supplying employees of various ranks with information to implement management functions.
An information system is created for a specific object. An effective information system takes into account the differences between levels of management, areas of action, and external circumstances and provides each level of management with only the information it needs to effectively implement management functions.
The introduction of information systems is carried out in order to increase the efficiency of the company’s production and economic activities through not only the processing and storage of routine information, automation of office work, but also through fundamentally new management methods based on modeling the actions of company specialists when making decisions (artificial intelligence methods, expert systems, etc.), the use of modern telecommunications (e-mail, teleconferences), global and local computer networks, etc.
Depending on the degree (level) of automation, manual, automated and automatic information systems are distinguished.
Manual ICs characterized by the fact that all information processing operations are performed by humans.
Automated ICs– some of the control or data processing functions (subsystems) are carried out automatically, and some are carried out by humans.
Automatic ICs– all control and data processing functions are carried out by technical means without human intervention (for example, automatic control of technological processes).
According to the scope of application, the following classes of information systems can be distinguished:
Scientific research;
Computer-aided design;
Organizational management;
Technological process management.
Scientific IP designed to automate the activities of scientists, analyze statistical information, and control experiments.
Computer-aided design IC designed to automate the work of design engineers and developers of new equipment (technology). Such information systems help to:
Development of new products and technologies for their production;
Various engineering calculations (determining technical parameters of products, consumption standards - labor, material, etc.);
Creation of graphic documentation (drawings, diagrams, layouts);
Modeling of designed objects;
Creation of control programs for numerically controlled machines.
IS of organizational management designed to automate the functions of administrative (managerial) personnel. This class includes IS for managing both industrial (enterprises) and non-industrial facilities (banks, stock exchanges, insurance companies, hotels, etc.) and individual offices (office systems).
Process Control IC designed for automation of various technological processes (flexible production processes, metallurgy, energy, etc.).
1.2.3 Structure and composition of the information system. Almost all types of information systems considered, regardless of their scope of application, include the same set of components (Fig. 1.2):
Functional components;
Data processing system components;
Organizational components.
At the same time, under control function refers to a special ongoing responsibility of one or more persons, the fulfillment of which leads to the achievement of a specific business result.
Under functional components is understood as a system of management functions - a complete set (complex) of management work interconnected in time and space, necessary to achieve the goals set for the enterprise.
The entire process of company management comes down to either linear (for example, administrative) management of the enterprise or its structural division, or to functional management (for example, logistics, accounting, etc.) Therefore, the decomposition of the information system according to functional criteria (Fig. 1.2) includes the identification of its individual parts, called functional subsystems (FS) (functional modules, business applications), implementing a system of management functions. The functional attribute determines the purpose of the subsystem, that is, for what area of activity it is intended and what main goals, tasks and functions it performs. Functional subsystems largely depend on the subject area (field of application) of information systems.
Figure 1.3 shows the functional decomposition of the information system of an industrial enterprise. Depending on the complexity of the object, the number of functional subsystems ranges from 10 to 50 items. As follows from the figures above, despite the different areas of application of information systems, a number of functional subsystems have the same name (for example, accounting and reporting), but their internal content for different objects differs significantly from each other. The specific features of each functional subsystem are contained in the so-called “functional tasks” of the subsystem (Fig. 1.2). Typically, management personnel either associate this concept with the achievement of certain goals of the management function, or define it as work that must be performed in a certain way in a certain period. However, with the advent of new information technologies, the concept of “ task » is considered more broadly: as a complete complex of information processing, providing either the issuance of direct control influences on the course of the production process, or the issuance of the necessary information for decision-making by management personnel. Thus, the task should be considered as an element of the control system, and not as an element of the data processing system. The choice of the composition of functional tasks of functional management subsystems is usually carried out taking into account the main phases of management: planning; accounting, control and analysis; regulation (execution).
Planning is a management function that ensures the formation of plans in accordance with which the functioning of the management object will be organized. Typically, long-term (5–10 years), annual (1 year) and operational (day, week, decade, month) planning are distinguished.
Figure 1.3 – Enlarged functional decomposition
industrial enterprise information system
Accounting, control and analysis– these are functions that provide data on the state of the managed system for a certain period of time; determining the fact and reason for deviations of the actual state of the control object from the planned state, as well as finding the magnitude of this deviation. Accounting is carried out according to plan indicators in the selected planning range (horizon) (operational, medium-term, etc.).
Regulation (execution)– this is a function that ensures a comparison of planned and actual performance indicators of a control object and the implementation of the necessary control actions in the presence of deviations from the planned ones in a given range (segment).
In accordance with the identified functional subsystems (Fig. 1.3) and taking into account the management phases, the composition of the tasks of the functional subsystems is determined. For example, a bank’s personnel management information system may contain the following functional subsystems:
Planning the number of bank personnel;
Calculation of personnel payroll;
Planning and organizing staff training;
Management of personnel movements;
Statistical accounting and reporting;
Help on request.
The selection and justification of the composition of functional tasks is one of the important elements of creating information systems. It should be noted that it is the task (functional subsystem) that is the object of development, implementation and operation by the end user.
Analysis of functional tasks shows that their practical implementation in information systems is multivariate. The same problem can be solved (implemented) by various mathematical methods, models and algorithms (Fig. 1.2). This functional subsystem is sometimes called software subsystem.
Among the many implementation options, as a rule, there is the best one, determined by the capabilities of the computing system and the data processing system as a whole.
In modern automation systems for the design of information systems, this component is part of the so-called banks of models and algorithms, from which the most effective ones for a specific management object are selected during the development of information systems.
1.2.4 Components of a data processing system. The main function of the data processing system is the implementation of standard data processing operations, which are:
Collection, registration and transfer of information to computer media;
Transfer of information to places of its storage and processing;
Entering information into a computer, controlling input and arranging it in computer memory;
Creation and maintenance of an in-machine information base;
Processing information on a computer (accumulation, sorting, adjustment, sampling, arithmetic and logical processing) to solve functional problems of the facility management system (subsystem);
Output of information in the form of tabs, videograms, signals for direct control of technological processes, information for communication with other systems;
Organization, management (administration) of the computing process (planning, accounting, control, analysis of the implementation of the progress of calculations) in local and global computer networks.
Data processing system (DPS) is intended for information services for specialists from various management bodies of the enterprise who make management decisions.
The identification of typical data processing operations made it possible to create specialized software and hardware systems that implement them (various peripheral devices, office equipment, standard software sets, including application software packages - APP - that implement the functional tasks of the IS). The configuration of hardware systems forms the so-called topology of the computing system.
ODS can operate in three main modes: batch, interactive, real time.
For burst mode It is typical that the processing results are given to users after completing so-called task packages. As an example of systems operating in batch mode, we can name systems of statistical reporting, tax inspectorates, cash settlement centers (CCS), banks, etc. The disadvantage of this mode is that the user is isolated from the information processing process, which reduces the efficiency of making management decisions.
At interactive (dialogue) mode operation, messages are exchanged between the user and the system. The user considers the results of the query and enters the decisions made into the system for further processing. Typical examples of dialogue tasks can be considered multivariate tasks of using resources (labor, material, financial).
Real time mode used to manage fast processes, such as the transfer and processing of banking information in global international networks such as SWIFT, and continuous technological processes.
Almost all data processing systems of information systems, regardless of their scope of application, include the same set of components (components), called types of support (Fig. 1.2). It is customary to distinguish information, software, technical, legal, and linguistic support.
Information Support is a set of methods and means for placing and organizing information, including classification and coding systems, unified documentation systems, rationalization of document flow and document forms, methods for creating an in-machine information base of an information system. The reliability and quality of management decisions made largely depends on the quality of the developed information support.
Software– a set of software tools for creating and operating ODS using computer technology. The software includes basic (system-wide) and applied (special) software products.
Technical support is a set of technical means used for the operation of a data processing system both outside a computer (peripheral technical means for collecting, recording, primary processing of information, office equipment for various purposes, telecommunications and communications equipment) and on computers of various classes.
Legal support is a set of legal norms regulating the creation and operation of an information system. Legal support for the development of an information system includes regulations on contractual relationships between the customer and the IS developer. Legal support for the functioning of ODS includes: conditions for giving legal force to documents obtained using computer technology; rights, duties and responsibilities of personnel, including for the timeliness and accuracy of information processing; rules for using information and the procedure for resolving disputes regarding its reliability, etc.
Linguistic support is a set of language tools used at various stages of the creation and operation of ODS to increase the efficiency of development and ensure communication between humans and computers.
1.2.5 Organizational components of the information system. The separation of organizational components into an independent direction is determined by the special importance of the human factor (personnel) in the successful functioning of the IS. Before implementing an expensive data processing system; A huge amount of work must be done to streamline and improve the organizational structure of the facility; otherwise, the efficiency of the IS will be low. the main problem at the same time, it consists in identifying the degree of compliance of existing management functions and the organizational structure that implements these functions and the company’s development strategy. The means to achieve the goal - improving organizational structures - are various modeling methods.
Under organizational components of IS (Fig. 1.2) is understood as a set of methods and means that make it possible to improve the organizational structure of objects and management functions performed by structural divisions; determine the staffing table and the number of members of each structural unit; develop job descriptions for management personnel in the operating conditions of the ODS.
1.2.6 Trends in the development of information systems. The logic of the development of information systems over the past 40 years clearly demonstrates the pendulum effect: the centralized data processing model based on mainframes, which dominated until the mid-80s, gave way in just a few years to the distributed architecture of peer-to-peer local networks (LANs) of personal computers, but then a return began movement towards centralization of system resources.
Today, the focus is on client-server technology, which effectively combines the advantages of its predecessors.
There are several generations of IP.
First generation IC (1960–1970) was built on the basis of central computers on the principle of “one enterprise - one processing center”, and the IBM operating system - MVS - served as a standard environment for executing applications (functional tasks).
Second generation IC (1970–1980): The first steps towards IP decentralization, during which users began to push information technology into offices and company branches using minicomputers such as DEC VAX. In parallel, the active introduction of high-performance DB2-type DBMSs and commercial application software packages began. Thus, the cardinal innovation of this generation of information systems was a two- and three-level model of organizing a data processing system (central computer - mini-computers of departments and offices) with an information foundation based on a decentralized database and application packages.
Third generation IC(1980–early 1990): Distributed network processing boom, driven by the massive shift to personal computers (PCs). The logic of corporate business required the unification of disparate jobs into a single information system - computer networks and distributed processing appeared. However, very soon the first signs of hierarchy began to be discovered in peer-to-peer networks: first in the form of dedicated file servers, print servers and telecommunications servers, and then application servers. At some stage, the increasing need for concentration of IS resources responsible for system administration (organizing the computing process), supporting the corporate database and running centralized applications associated with it, was satisfied in the so-called “medium caliber” model through the use of UNIX servers , produced by IBM, DEC, Hewlett-Packard, Sun, etc. Therefore, the server market has become one of the most dynamic sectors of the computer industry.
With the development of third-generation IS, the idea of pure (peer-to-peer) distributed processing noticeably faded and gave way to a hierarchical client-server model.
Fourth generation IC. The distinctive features of modern IS are, first of all, a hierarchical organization in which centralized processing and unified management of IS resources at the upper level is combined with distributed processing at the lower level, determined by the synthesis of solutions tested in systems of previous generations. Fourth generation information systems accumulate the following main features:
Fully exploit the potential of desktop computing and distributed processing environments;
Modular construction of the system, suggesting the existence of many different types of architectural solutions;
Saving system resources by centralizing data storage and processing at the upper levels of the IS hierarchy;
Availability of effective centralized network and system administration tools (organization of the computing process), allowing end-to-end control over the functioning of the network and management at all levels of the hierarchy, as well as providing the necessary flexibility and dynamic changes in the system configuration;
A sharp reduction in the so-called “hidden costs” - operating costs for maintaining the information system, which are not easy to provide for in the organization’s budget (maintaining the functioning of the network, backing up user files on remote servers, setting up the configuration of workstations and connecting them to the network, ensuring data protection, updating versions software, etc.).
1.3 Classification and structure of technical means of information technology
1.3.1 Stages of information systems operation
1.3.2 Basic information about the computer design
1.3.3 Computer classification
1.3.4 Computer development trends
Literature: 2 p. 48–76; 4 c. 32–73; 5 c. 45–56; 6 c. 4–12, 92–136; 8.9.
1.3.1 Stages of information systems operation. In the operation of an information system, in its technological process, several fairly clearly distinguishable stages can be distinguished:
1. The Birth of Data, i.e., the formation of primary messages that record the results of business operations, the properties of objects and subjects of management, parameters of production processes, the content of regulatory and legal acts, etc.
2. Accumulation and systematization of data , i.e., organizing such a placement of data that would ensure quick search and selection of the necessary information, methodical updating of data, protection from distortion, loss, loss of connectivity, etc.
3. Data processing – processes as a result of which, on the basis of previously accumulated data, new types of data are formed: generalizing, analytical, recommendatory, forecasting... Derived data can also be subjected to further processing and bring information of deeper generalization, etc.
4. Data display – presentation of data in a form suitable for human perception. First of all, this is printing, i.e., the production of documents that are convenient for human perception. But such types of presentation as the construction of graphical illustrative materials (graphics, diagrams) and the formation of sound signals are also widely used.
1.3.2 Basic information about the computer structure. An electronic computer (computer) is a device that performs the following operations:
Entering information;
Processing information according to the computer program;
Output of processing results in a form suitable for human perception.
A special computer block is responsible for each of these actions, respectively: input device, central processing unit (CPU), output device. All of them are very complex and, in turn, consist of separate smaller devices. In particular, the central processor may include: an arithmetic-logical unit, a control device, and a random access memory device. Thus, the enlarged block diagram of the computer takes on the form shown in Fig. 1.4. This composition was first formulated by the German-American mathematician John von Neumann (although it was first used during the Second World War by the German Konrad Zuse in his Z-series calculators).
Arithmetic logic unit (ALU) is exactly the place where data transformations prescribed by program commands are performed: arithmetic operations on numbers, code conversions, word comparison, etc.
Random Access Memory (RAM), or simply memory, is designed to host programs, as well as to temporarily store some parts of input data and intermediate results. It is characterized by: the ability to write (or read) elements of programs and data to an arbitrary memory location (or from an arbitrary memory location), high performance. Word arbitrary does not mean “whatever”, but the opportunity to turn to given address without necessity viewing everyone previous.
Figure 1.4 – Enlarged block diagram of a computer
Computer quality characterized by many indicators. This is a set of instructions (commands) that a computer is capable of understanding and executing, and the operating speed (performance) of the central processor, and the number of input/output devices (peripheral devices) that can be connected to it at the same time, and power consumption, and much more. But the main characteristic, as a rule, is performance , that is, the number of operations that the central processor is capable of performing per unit of time.
The speed of a computer significantly depends on the speed of the RAM, or in other words, on the duration of access to the RAM. Therefore, there is a constant search for RAM elements that would require as little time as possible for read-write operations. However, along with performance, the cost of memory elements increases (and very sharply), so building RAM of the required capacity on fast elements is economically unacceptable. This problem was resolved by building multi-level memory . RAM consists of two or three parts: the main part is large in capacity, built on relatively slow (but cheaper) elements, and the additional part (it is called cache memory ) consists of high-speed elements. The data that the ALU accesses most frequently is contained in the cache; a larger amount of operational information is stored in main memory. The distribution of information between the components of RAM is controlled by a special unit of the central processing unit (CPU). The amount of RAM and cache memory is one of the most important characteristics of a computer.
1.3.3 Classification of computers. The range of types of computers is currently huge: machines differ in purpose, power, size, element base used, resistance to adverse conditions, etc. So it would be possible to classify computers from different points of view, according to different classification criteria. The currently accepted gradation of computers in terms of performance and overall characteristics (dimensions, weight) is presented in Table 1.1. It should be noted that the classification is to a certain extent arbitrary, since the boundaries between groups are blurred and very fluid over time: the development of this branch of science and technology is so rapid that, for example, today's microcomputer is not inferior in power to a minicomputer five years ago.
Table 1.1 – Classes of modern computers
| Computer class | Main purpose | Basic technical data |
| Supercomputer | Complex scientific calculations | Integral performance up to hundreds of billions of operations per second; hundreds of parallel processors |
| Mainframe computers | Processing large volumes of information from banks and large enterprises | Multiprocessor architecture; connection of up to 200 workstations |
| Minicomputer | Management systems for medium-sized enterprises; multi-console computing systems | Multiprocessor architecture, extensive peripherals |
| Servers | Control of local network or Internet node, data storage | Single (multi-processor) architecture, high processor speed; large RAM, large capacity hard disk drives |
| Workstations | Computer-aided design systems, experiment automation systems | Single (multi-processor) architecture, high processor speed; large RAM, large capacity hard drives, specialized peripherals |
| Microcomputer | Personalized user service; work in local automated control systems | Single-processor architecture, configuration flexibility - ability to connect a variety of external devices |
Class of personal computers itself consists of very diverse types of machines and therefore deserves a separate classification (Table 1.2). Weight and dimensions data were taken as a classification criterion.
Table 1.2 – Microcomputers (personal computers)
| Type | Weight, kg | Power supply |
Information systems design always begins with defining the goal of the project. In general terms, the goal of the project can be defined as solving a number of interrelated tasks, including ensuring at the time of system launch and throughout the entire period of its operation:
- the required functionality of the system and the level of its adaptability to changing operating conditions;
- required system throughput;
- required system response time to a request;
- trouble-free operation of the system;
- required level of security;
- ease of operation and system support.
According to modern methodology, the process of creating an IS is a process of constructing and sequentially transforming a number of consistent models at all life cycle stages(LC) IS. At each stage of the life cycle, models specific to it are created - organization, IS requirements, IS project, application requirements, etc. Models are formed by working groups of the project team, saved and accumulated in the project repository. The creation of models, their control, transformation and provision for collective use is carried out using special software tools - CASE tools.
The process of creating IP is divided into a series stages(stages [1.1]), limited by a certain time frame and ending with the release of a specific product (models, software products, documentation, etc.).
Usually the following are distinguished stages of IP creation: formation of system requirements, design, implementation, testing, commissioning, operation and maintenance [1.1] [1.2]. (The last two stages are not discussed further as they are beyond the scope of the course.)
The initial stage of the IS creation process is the modeling of business processes occurring in an organization and realizing its goals and objectives. The organization model, described in terms of business processes and business functions, allows us to formulate the basic requirements for the IS. This fundamental position of the methodology ensures objectivity in developing system design requirements. The set of models for describing IS requirements is then transformed into a system of models that describe the conceptual design of the IS. Models of IS architecture, requirements for software (SW) and information support (IS) are formed. Then the software and information architecture is formed, corporate databases and individual applications are identified, application requirements models are formed and their development, testing and integration are carried out.
The purpose of the initial stages of IP creation carried out at the stage of analyzing the organization’s activities, is the formation of requirements for information systems that correctly and accurately reflect the goals and objectives of the customer organization. To specify the process of creating information system that meets the needs of the organization, it is necessary to find out and clearly articulate what these needs are. To do this, it is necessary to determine customer requirements for the IS and map them in model language into the requirements for developing an IS project so as to ensure compliance with the goals and objectives of the organization.
The task of forming requirements for information systems is one of the most important, difficult to formalize, and the most expensive and difficult to correct in the event of an error. Modern tools and software products allow you to quickly create IP according to ready-made requirements. But often these systems do not satisfy customers and require numerous modifications, which leads to a sharp rise in cost actual cost IS. The main reason for this situation is the incorrect, inaccurate or incomplete definition of IS requirements at the analysis stage.
At the design stage, data models are first formed. Designers receive analysis results as initial information. Building logical and physical data models is the main part database design. The information model obtained during the analysis process is first converted into a logical one, and then into physical data model.
In parallel with design database schemas Process design is carried out to obtain specifications (descriptions) of all IS modules. Both of these design processes are closely related because some of the business logic is usually implemented in the database (constraints, triggers, stored procedures). The main goal of process design is to map the functions obtained during the analysis phase into modules of the information system. When designing modules, program interfaces are determined: menu layout, window appearance, hot keys and related calls.
The final products of the design phase are:
- database diagram (based on the ER model developed at the analysis stage);
- kit module specifications systems (they are built on the basis of function models).
In addition, at the design stage, the development of the IS architecture is also carried out, including the selection of platform (platforms) and operating system (operating systems). In a heterogeneous IS, several computers can run on different hardware platforms and running different operating systems. In addition to choosing a platform, the following architecture characteristics are determined at the design stage:
- whether it will be a file-server or client-server architecture;
- will it be a 3-tier architecture with the following layers: server, middleware (application server), client software;
- whether the database will be centralized or distributed. If the database is distributed, then what mechanisms will be used to maintain data consistency and relevance;
- whether the database will be homogeneous, that is, whether all database servers will be products of the same manufacturer (for example, all servers are Oracle only or all servers are DB2 UDB only). If the database is not homogeneous, then what software will be used to exchange data between DBMSs from different manufacturers (already existing or specially developed as part of the project);
- will parallel database servers (for example, Oracle Parallel Server, DB2 UDB, etc.) be used to achieve proper performance?
The design phase ends with development technical project IS.
At the implementation stage, the system software is created, hardware is installed, and operational documentation is developed.
The testing phase is usually distributed over time.
As part of corporate information systems, two relatively independent components can be distinguished:
· computer infrastructure of the organization, which is a set of network, telecommunications, software, information and organizational infrastructures. This component is usually called the corporate network.
· interconnected functional subsystems that ensure solving the organization’s problems and achieving its goals.
The first component reflects the system-technical, structural side of any information system. In essence, this is the basis for the integration of functional subsystems, which completely determines the properties of the information system that determine its successful operation. The requirements for computer infrastructure are uniform and standardized, and the methods for its construction are well known and have been tested many times in practice.
The second component of the corporate information system is entirely related to the application area and strongly depends on the specific tasks and goals of the enterprise. This component is completely based on the computer infrastructure of the enterprise and determines the applied functionality of the information system. The requirements for functional subsystems are complex and often contradictory, as they are put forward by specialists from various application areas. However, ultimately, it is this component that is more important for the functioning of the organization, since, in fact, the computer infrastructure is built for it.
The relationship between the components of the information system
The relationships between the two indicated components of the information system are quite complex. On the one hand, these two components are independent in a certain sense. For example, the organization of a network and the protocols used to exchange data between computers are absolutely independent of what methods and programs the enterprise plans to use to organize accounting.
On the other hand, these components, in a certain sense, still depend on each other. Functional subsystems, in principle, cannot exist without computer infrastructure. At the same time, the computer infrastructure itself is quite limited, since it does not have the necessary functionality. It is impossible to operate a distributed information system in the absence of network infrastructure. Although, having a developed infrastructure, it is possible to provide the organization's employees with a number of useful system-wide services (for example, e-mail, Internet access) that simplify work and make it more efficient (in particular, through the use of more advanced communication tools).
Thus, it is advisable to begin the development of an information system with the construction of a computer infrastructure (corporate network) as the most important component, based on proven industrial technologies and guaranteed to be implemented within a reasonable time and with a high degree of certainty both in the statement of the problem and the proposed solutions.
Note
It makes no sense to build a corporate network as a kind of self-sufficient system without taking into account application functionality. If in the process of creating a system-technical infrastructure you do not analyze and automate management tasks, then the funds invested in the development of a corporate network will not subsequently give a real return.
The corporate network is created for many years in advance; the capital costs for its development and implementation are so high that they practically exclude the possibility of complete or partial reworking of the existing network. Functional subsystems, in contrast to the corporate network, are changeable in nature, since more or less significant changes are constantly occurring in the subject area of the organization’s activities. The functionality of information systems strongly depends on the organizational and managerial structure of the organization, its functionality, distribution of functions, financial technologies and schemes adopted in the organization, existing document flow technology and many other factors.
The development and implementation of functional subsystems can be done gradually. For example, first, in the most important and responsible areas, carry out developments that ensure the application functionality of the system (implement financial accounting systems, personnel management, etc.), and then distribute application software systems to other, initially less significant areas of enterprise management.
Questions:
1. Stages of development of information systems?
2. General properties characteristic of information systems?
3. What are the main components of corporate information systems?
4. What are the relationships between the components of the information system?
Lecture 3
Topic: Areas of application and examples of implementation of information systems. Life cycle of information systems.
Plan
1. Scope of information technology;
2. Examples of implementation of information systems;
3. Life cycle of information systems
Keywords
Software product, corporate information systems, IS components, computer infrastructure, interconnected functional subsystems, corporate network, IS life cycle.
Areas of application and examples of implementation of information systems
Over the past few years, the computer has become an integral part of the management system of enterprises. However, the modern approach to management also involves investing in information technology. Moreover, the larger the enterprise, the greater such investments should be.
Thanks to the rapid development of information technology, the scope of their application is expanding. If previously almost the only area in which information systems were used was accounting automation, now we are seeing the introduction of information technologies into many other areas. Effective use of corporate information systems allows you to make more accurate forecasts and avoid possible management errors.
A lot of useful information can be extracted from any data and reports on the operation of an enterprise. And information systems make it possible to extract maximum benefit from all the information technologies available to the company - modern business is extremely sensitive to management errors, and in order to make competent management decisions in conditions of uncertainty and risk, it is necessary to constantly keep under control various aspects of the financial and economic activities of the enterprise (regardless of the profile of his activity).
Therefore, it can be quite reasonably stated that in a tough competition, an enterprise that uses modern information technologies in management has a great chance of winning.
Let's look at the most important tasks that can be solved using special software.
Accounting
This is a classic area of application of information technology and the most frequently implemented task today. This situation is quite understandable. First, an accountant's mistake can be very costly, so the benefits of using accounting automation capabilities are obvious. Secondly, the accounting task is quite easily formalized, so the development of accounting automation systems does not pose a technically difficult problem.
Note
However, the development of accounting automation systems is very labor-intensive. This is due to the fact that accounting systems are subject to increased requirements in terms of reliability and maximum simplicity and ease of use.