A system is a group of elements that work or support together to achieve a common goal or goal.
A system must be fed through the entry of a resource (input), in order to activate the elements of the system (process) and thus produce the required results (output). Based on this model, the systems allow to solve a number of eventualities, which from now on we will call EPS (it comes from Input Process Output).
For example, the digestive system advises the need for food that the user should eat when energy and essential nutrients are required. Once the amounts of food have been entered, the body will be in charge of carrying out the digestion process, resulting in the absorption of essential nutrients and the disposal of undesirable material. Graphically we would be talking about:
This system will remain in harmony, as long as the inputs are adequate and the process is not injured in one of its elements. A system failure involves an undesirable output or one that does not meet the planned objective.
The conditions for a system to exist are:
- Have a general objective There must be an interrelation of elements that work towards the same objective They must fulfill a series of logical and functional steps that allow differentiating the inputs, the process and the outputs of the system.
Systems can be divided into other smaller differentiable systems called subsystems. An output of a subsystem can become the input of another subsystem, it should also be mentioned that a system is related to other external systems, which can directly or indirectly affect its operation.
THE OBJECTIVE IN SYSTEMS
The systems fulfill a basic or main function, therefore, all the elements will be aimed at pursuing that end. In our symbology, the objective of a system corresponds to the result or results obtained. Without an end, a system has no reason to exist. This ratio is the analysts' starting point for a thorough and comprehensive study of a system.
If an element does not add value to reach the goal, the system must eliminate it. All elements must be directed or focused on their primary objective, no matter how they act to achieve it.
Among the characteristics that frame an objective of a system, we have:
- The objective summarizes the functions carried out in a system: It gives us an idea of what and why things are done. The objective gives an impression about the size and space of a system: To what extent it has its scope and what its limitations are. The objective is clearly measurable: Either by direct observation, indicators, comparisons and analysis of the convenience of results. A goal is achieved or not achieved.
A separate chapter will be devoted to the measurement and analysis of the objectives.
THE ELEMENTS THAT MAKE UP A SYSTEM
The term "ELEMENTS" is a broad point of view of the contents of a system. In them we can find and identify: activities, sequences, processes, procedures, methods, resources and controls.
Without an element it does not add value within the system, it must be eliminated, since it will simply consume necessary resources that can serve other elements, or it will simply be a hindrance, and if it does not help to achieve the objective, it would be easier in the long run to do without of him, to keep it. A heart by itself is of no use, but if it is linked to the human body, it follows that its contribution is to drive the blood throughout the body carrying oxygen, energy, antibodies and nutrients.
If an element fails, the objective may or may not be achieved, depending on the importance and contribution that this element has within the system. What is certain is that if the objective were to be achieved, the quality of response (characteristics, delivery time, conditions) would be affected and its efficiency would be reduced.
Decomposing a system into each of its elements is a fundamental task for the analyst. Without this step, a thorough understanding of its function, the possibilities for improvement or modification, its scope and limitations is unlikely.
Next we will define the key elements that must be taken into account for the correct definition of a system:
The activities: In this aspect we will dedicate a complete chapter, until now we will say that they are procedures or functions that must be carried out with limited resources (inputs, human capital, cost, time and sequence), to achieve a greater objective.
The sequences: It is the logical and systematic order with which the activities are carried out (prerequisites of an activity).
The methods: It is defined as a set of ordered steps that allow to achieve a goal or objective in a particular way.
The procedures: It is to apply a specific method within a broad framework of problem solving. An activity consists of one or more procedures to be carried out.
Resources: These are the inputs and supplies that a system needs to function. We find resources in the inputs (primary resources: energy, design, materials, information, data) and in the processes (machinery, human resources, monetary capital, technology, time).
The controls: They allow us to verify the steps followed by the process, from its inputs to the achievement of goals or general objective, it is being carried out, as the system was conceived. Thanks to the controls, feedback or feedback can be carried out, in order to improve efficiency and effectiveness. Without controls, a system cannot guarantee that it will produce results that are consistent with its objective.
Isolating a system from other similar systems or the environment in which it is located is another fundamental step and perhaps the most difficult. Until when it is no longer a priority procedure for a department in a company; what variables can affect the performance of a sector; when the atmospheric conditions of a locality do not affect the neighboring localities; this and other examples are presented in the detailed and "correct" study.
CLASSIFICATION OF SYSTEMS
There are three general types of systems we encounter in our daily lives: The natural systems, the artificial systems and third party resulting from the combination of both, which we call composite systems. Each one has particular characteristics, but with identical bases within systems theory.
Natural systems are born in response to physical, chemical and biological phenomena created by nature.
Artificial systems are those that were achieved by the direct intervention of the human race. It actively participated in its design, management, control and execution. These systems can be called human systems.
Compound systems occur when in a natural system there is the participation of an external force manipulated by the human being directly or indirectly. Among the concrete examples we have: manipulation of the immune system, change of environmental conditions, adaptation of ecosystems due to the appearance of cities.
COMPLETE EXAMPLE OF A SYSTEMS ANALYSIS
THE COMPUTER
The computer is an electronic and mechanical machine (hardware), governed by programs (software) that allow data to be processed and stored in a quick and orderly way. The computer is a complete system, where the inputs, the process and the outputs are clearly identified as described below.
COMPUTER SYSTEMS
A computer system is made up of one or more electro-mechanical equipment (computers or other devices) supported by specific programs to carry out tasks or solve problems.
THE OBJECTIVE OF A COMPUTER SYSTEM
It is to solve one or more problems through a logical sequence that lists the following principles:
Data entry: Through specialized devices the data that comes from a user is entered (it can be a human person, another system or generated in the same process).
Process: Thanks to a series of operations, the relationship, analysis, storage, management and consolidation of the supplied data is created.
Data output: It is the result thrown by the process, which can be data for a new system or information for the user.
Let's remember the difference between two words: data and information. The data are values that by themselves are meaningless (for example, the value 15%). The information has a meaning for someone (for example, 15% of the displaced live in absolute poverty).
HOW IS DATA INPUT AND OUTPUT IN A COMPUTER SYSTEM?
As we said before, that data inputs and outputs are possible due to a series of devices called peripherals. These in turn can be classified into:
Input Peripherals: They allow me to enter data to the system or equipment. These can be: the keyboard, the mouse, the scanner, the optical pen, the microphone, among others.
Output Peripherals: They show the results required by the user. The most common are the screen, the printer and the speakers.
Input and Output Peripherals (I / O): They fulfill data input and output functions. Touch screens and some virtual reality devices can be mentioned.
Peripherals will fulfill their role if they do not fail or interrupt direct communication between all elements.
HOW IS THE PROCESS PERFORMED?
The process is carried out by a large number of mechanisms, mostly electronic, called the CPU or Central Processing Unit (in English C entral U nit P rocess).
The processor is composed of two main parts that describe its operation: The processing unit and the storage unit.
PROCESS UNIT
It is the brain of the computer and is generally integrated by a chip with the capacity to perform millions of operations per second.
Once it receives input data, the processor maintains logical and arithmetic operations aimed at breaking down and handling until the expected result is achieved. Operations are directed by software (as we will see later) that tells you exactly what data is necessary and how it should be treated.
Let us remember that a computer is a machine with the ability to manipulate and store data and, as it is composed of electronic circuits, it is not able to understand the same language code that human beings use. A computer works by transforming data into a series of high and low voltages represented in our jargon as zeros (for low voltages) and ones (for high voltages).
Every circuit has these two basic states. For your understanding we can imagine a circuit made up of a battery, a switch and a lamp. When the switch is on, it allows the passage of current, therefore the lamp turns ON; we represent this state with a one (1). Otherwise, the switch will be off and the lamp will not illuminate (OFF); We represent this state with a zero (0).
In the world of logic (Boolean algebra) both states correspond to true (one) or false (zero).
Code that only handles two values is called binary code. Each letter or number in our system will have an equivalent of zeros and ones. For example, two (2) in decimal system is equal to 0011 in binary system. This is the reason for being that the computer can only perform arithmetic and logical operations. Each 0 and 1 is called BITS (It is an abbreviation of the English expression BI nary digi T), that is, a BIT is equivalent to the minimum unit of measurement of the binary system.
As these values are increased, it is necessary to use an appropriate equivalence scale as shown in the following table:
| VALUE | EQUIVALENCE |
| 1 BYTE | 8 BITS |
| 1 KILOBYTES (KB) | 1024 BYTES |
| 1 MB (MB) | 1024 KB |
| 1 GIGABYTES (GB) | 1024 MB |
| 1 TERABYTES (TB) | 1024 GB |
The letters that we type with the keyboard and the characters that appear on the screen and printer are processed by a "translator" circuit (encoder or decoder) that converts them into binary language, and vice versa. Such a circuit looks for equivalences in a table of rows and columns that serves as a dictionary to translate words from one language to another. The most used tables are ASCII and ANSI, with a capacity of 256 characters, but they must be moved by the UNICODE table, for 65,536 characters. A character will have an amount of 8 BITS, which is the same as saying that it occupies a BYTES of memory.
A program that is designed directly under the binary language is created by means of a low-level language or machine language, with the advantage of being a fast program, but with the disadvantage of being very difficult to elaborate, due to the high degree of complexity with handling 0 and 1.
Many processors divide these two functions and make them independent of each other within the chip. Processor speed is measured in Hertz and is scaled similar to the units represented in binary code (1 Hertz equals 1024 KiloHertz, etc.).
STORAGE UNIT
To meet the designated objective, the processor needs a place where it can store that amount of input data and processed data. These areas are called storage units.
There are two types of basic storage units, fixed or permanent units and temporary units.
Fixed or permanent storage units: These fulfill, as their name implies, the function of saving data permanently, even without the need for energy to keep it running. These types of units include: hard drives, floppy disks, CDs, DVDs, ROM (Read Only Memory).
Temporary storage units: They store the data as long as the device is continuously supplied with power. Without power, data will be lost. Examples include: RAM (Read Aleatory Memory), CACHE memory, and FLASH memory.
Other characteristics that allow us to differentiate these two types of memory are:
- Fixed or permanent disks generally have a capacity many times greater compared to temporary memory. Being made up of a series of integrated circuits and silicon boards, temporary memory is much faster than temporary memory.
THE PROGRAMS: CONTROLLING A COMPUTER SYSTEM
The software or programs are responsible for operating the equipment or hardware of a computer system and provide the keys to the process or development of solutions to specific problems.
Software is classified according to its function within the computer system in:
- Low-level language: As we explained in the section on the process of a computer system, it is responsible for converting the data supplied into binary code that can be managed by the computer and vice versa. High-level language: They are responsible for making programs called applications (and even Operating Systems) using an intermediate language similar to human language. Applications: They are programs with a main objective or only function. Among these types of software we have: word processors, spreadsheets, music players, among others. Operating Systems: Unlike applications, they do not have a unique function; Instead they have three main characteristics:
- It manages the memory of the computer. It serves as a platform for the execution of applications. It allows to send orders to the devices or hardware.
Once the explanation of hardware and software is finished, we can clearly observe their interrelation, taking as the first example of a complete system.
PHYSONOMY OF A COMPUTER SYSTEM
We will focus on specifying how the system works, without using a specific example of an answer. Only the elements explained previously will be used, new elements will be omitted to facilitate their explanation.
The system begins with a user or team which enters information to the system according to previously established parameters. The data provided must be exact, not differing from the application that will receive and process it; if this occurs, the program will not run or will produce the expected results. These data are usually written in a different system than the binary system.
Download the original file
