System implementation of management information system for excellent courseware notes

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System implementation of management information system
Section 1 Implementation of physical systems
The implementation of the MIS physical system is the sum of system activities such as ordering of computer systems and communication network system equipment, preparation of data centers, installation and debugging of equipment.
I. Implementation of computer systems
The basic principle of purchasing a computer system is to meet the design requirements of MIS.
In addition, the following questions should also be considered: whether the computer system has a reasonable performance-to-price ratio
Whether the system has good scalability
Can you get after-sales service and technical support from suppliers.
II. Implementation of the network system
MIS is usually a network system composed of a line to connect various devices.
MIS Network: a LAN usually refers to a network within a certain range, which can realize internal connections between the building and adjacent buildings.
Communication between Wide Area Network (WAN) devices usually uses public telecommunication networks to implement communication between remote devices.
Main content of network system implementation: installation of communication equipment;
Laying of cables;
Debugging of network performance.
Common communication lines include twisted pair wires, coaxial cables, optical fiber cables, and microwave and satellite communications.
Section 2 Program Design
I. Requirements for programming
Maintainability: it is easy to supplement or modify programs when system requirements change.
Reliability: Not only can it work properly under normal circumstances, but it should be easy to handle in case of accidents.
Understandable: requires a clear hierarchy for easy reading and maintenance.
Efficiency: Program Efficiency refers to whether a program can effectively use computer resources, such as saving storage space and improving operation efficiency. However, the one-sided pursuit of program operation efficiency is not conducive to the overall improvement of the quality of program design, because efficiency and maintainability and comprehensibility are usually in conflict.
2. Structured Program Design Method-1
• Programming should be in line with the idea of software engineering, that is, engineering methods should be used for software development. This not only improves software development efficiency, but also facilitates future maintenance and modification.
Specifically: the top-down modular design method should be adopted as a whole;
In specific programming, the structured programming method should be used.
2. Structured Program Design Method-2
• Top-down Modular Design
First, determine the upper-layer functions. Then, after layer-by-layer decomposition, a complex system is divided into multiple function modules with a single function.
Pay attention to the following points in modular program design:
-Module independence: independent modules should be developed independently as much as possible.
-The module size should be properly divided, and the number of sub-modules included in the module should be appropriate.
-Simple module functions: the underlying module should generally complete an independent processing task.
-Shared function modules should be concentrated in an upper-layer module for reference by each module.
2. Structured Program Design Method-3
• Structured Programming Method: It features the following three basic logical structures for programming:
Sequence Structure: it consists of a series of statements or modules that are executed in sequence.
Loop Structure: The loop structure is composed of one or more modules. It is executed repeatedly when the program runs until a certain condition is met.
For example, the do while-enddo statement in FoxPro is in the following format:
Do While <condition>
<Command Group 1>
[Loop]
<Command Group 2>
[Exit]
<Command Group 3>
Enddo
Ii. Structured Program Design Method-4
3. Select the structure and select the program execution path based on the conditions.
Software development tools
• In the past, applications were written by professional computer workers in a row-by-row manner. They were not only long, inefficient, of poor quality, but also repetitive and difficult to modify. Software development tools can solve these problems to a certain extent.
I. spreadsheet software
For example, the Lotus 1-2-3 workbook package has a large Worksheet (256 columns * 2048 rows ). You can enter the table data on the screen through the keyboard, store the data in the database, and display or print the data in a graphic manner. Because this software can flexibly convert other types of data files into worksheet files, it is more convenient to use. In addition, Lotus 1-2-3 has also set many common functions and models in statistics and accounting, thus facilitating the development of MIS and DSS.
Ii. Use the generation function of the Database Management System
Currently, the database management system is not limited to data management, but also has powerful software generation functions. For example:
In the Oracle database management system, you can use SQL * forms to conveniently perform database operations by selecting menus and corresponding function keys;
SQL * Plus triggers provide necessary testing methods to ensure data integrity, consistency, and legitimacy. SQL * Report provides convenience for report output.
SQL * graph provides convenience for Graph Generation.
These Oracle software tools can be used together to form a comprehensive application software development environment.
3. Software Package
Software kits are software that integrates popular software. For example, office integrates the following software: Word (word processing software) Excel (spreadsheet software) Power Point (drawing software ).
This set of software can use word processing, table design, database and drawing functions at the same time, Excel also has a certain scale of model generation functions.
Iv. Visual Programming tools
For example, Visual Basic combines object-oriented technology and provides a programming environment that uses objects. It provides users with a common language that can span multiple software platforms (such as spreadsheet software, fox-Pro type databases, word processing software, and drawing software.
Software developers can easily connect to other software by mastering a core language and see the same user interface.
V. Computer Aided Software Engineering (CASE)
Computer aidtd software engsneering (CASE ). It integrates multiple tools.
Implementation: • assisted programming
• Supports System Analysis and System Design (such as generating data flowcharts, generating function charts, and various documents ). It provides a full-process development environment for the system.
Section 4 program and system debugging
• Program and system debugging aims to discover possible errors in programs and systems and promptly correct them.
I. program debugging-1
Only after debugging can the program be considered to be basically correct, and to prove that the program is completely correct, it must be tried for a period of time before it can be determined.
Program debugging includes: 1. Whether the code test and testing program is logically correct; 2. whether the program function test and testing program can meet functional and application requirements.
I. program debugging-2
1. Check whether the code test program is logically correct.
First, compile the data to be tested,
Including normal data, abnormal data, and error data.
Then, (1) use normal data debugging (2) use abnormal data debugging, for example, use an empty data file to test whether the system can run normally. (3) debugging with error data, for example, whether the system can promptly discover and prompt error information when inputting error data or unreasonable data, and allow modification; for example: when an operation error occurs (including incorrect operation steps or methods), can the system issue a prompt warning and allow correction.
I. program debugging-3
2. When testing program functions, you must test the program's application environment.
As a "black box" to test whether it can meet functional and application requirements.
Ii. debugging (function debugging)
Purpose: To ensure a correct control relationship among the programs in the module and to test the module running efficiency.
Time of commissioning: After debugging of a single program is completed.
Debugging: concatenates all programs in a function in sequence for debugging.
Iii. Overall adjustment (executable joint adjustment)
Contents of the general adjustment: 1. The purpose of debugging the main control program and scheduling program is not to verify the correctness of the processing result, but to verify the correctness of the control interface and parameter transfer, so as to discover and solve the logic control problem. 2. General program debugging: connects the main control and scheduling program with each function module for overall debugging. At this stage, errors and defects in the relationship between modules are often identified. The overall adjustment should be conducted by system analysts and programmers.
4. Special tests and above are general tests.
Special tests are performed based on system requirements, such as-Peak Load Test-Capacity Test-Response Time Test-recovery capability test.
5. Real-time testing: the data obtained from the previous manual processing is used as the input, and the output results of the new system are compared with those of the manual processing. In addition to strict verification results, the rationality, efficiency and reliability of system operation should also be checked.
Section 5 system switching, Operation and Maintenance
I. system switching-1
System switching refers to the transition from an old and manual processing system to a new computer information system. Information system switching method: (1) Direct switching method (2) parallel switching method (3) pilot transition method
I. system switching-2
• Information system switching method
(1) Direct switching means that the new system is immediately put into operation when the old system stops running at a specified time.
(2) The parallel switching method runs for a period of time between the new system and the old system, compares the two outputs, and checks the new system based on the data of the old system.
(3) The parallel switching method replaces the old system with a part of the new system as a pilot and gradually replaces the old system.
I. system switching-3
• Precautions during system switching
1. Prepare the large amount of basic data required for new system projection as soon as possible
2. Not only is the conversion of programs, but more difficult is manual conversion. personnel should be trained in advance.
3. Some local problems occur during system switching, which can be solved in a timely manner.
Ii. system operation management and maintenance-1
• Routine management of system operation (completed by the system administrator)
-Sorting and distributing system output results
-In addition to recording normal conditions (such as processing efficiency, file access rate, and update rate), the system operation records must also record the time, cause, and handling result of the unexpected situation.
-Daily management of hardware and facilities
Ii. system operation management and maintenance-2
• System Maintenance includes:-program maintenance refers to modifying programs in part or whole based on changes in requirements or hardware environments.
-Data File Maintenance generally uses the File Maintenance Program provided by the developer, or you can compile a dedicated File Maintenance program on your own.
-Code maintenance, such as correction, addition, deletion, and redesign.
Section 6 Project Management and System Evaluation
• Management Information System Development and implementation involves a wide range of time, is a complex system engineering, requires the close cooperation of many personnel and scientific project management.
I. Personnel Management
• Talent required for the development and application of management information systems
-System staff-programmer-operation-hardware staff-project owner
• Project development should also be attended by management personnel, and the understanding and communication between users and designers should be strengthened. • The relationship between computers and users is the understanding and communication between computers serving users rather than computers.
Ii. Develop and implement the project work plan
• In order to complete system development, a project work plan should be prepared, the completion of the plan should be checked frequently, the reasons for the lag should be analyzed, and the plan should be adjusted in a timely manner.
• Plan development can adopt the Carter diagram or network plan technology to achieve the predefined goal with the shortest time and minimum resource consumption.
3. Develop relevant documents
• Appropriate documents should be prepared at each stage of MIS Development to clarify the work objectives and responsibilities.
Iv. System Evaluation
The purpose of the system evaluation is to review the operation process and performance, and check whether the system has achieved the expected goal, whether various resources in the system are fully utilized, and whether the management work is complete, in addition, the author proposes the aspects of system improvement and expansion in the future.
• System evaluation content-function evaluation of information systems-evaluation of current hardware and software-Application Evaluation of information systems-Evaluation of Economic Effects of Information Systems
• Section 7 system implementation from structured systems to object-oriented methods
I. Proposal of a rational and unified system development method-1
Question: The development success rate of management information systems has been very low. It is estimated that the success rate of Chinese enterprises developing information systems in 1980s is only about 20%, which means a large amount of money is wasted and lost.
The solution involves many related factors such as management ideas, management systems, management methods, power structures, obstacles to habitual forces, and development methods.
Key issues • identifying requirements, correctly describing requirements • Accelerating programming and allowing quick modifications
• Smooth integration of various stages of System Development
I. Proposal of a rational and unified system development method-2
Solving Key Problems • identifying requirements and correctly describing requirements
The model created through the rational UML (Unified Modeling Language) can define and describe the objective system more realistically and comprehensively.
• Speed Up Program Design and allow quick modifications
Switching from a structured programming method to an object-oriented programming method greatly speeds up program design. The design software is highly reusable, easy to maintain, and adaptable.
• Smooth connection between various stages of System Development
UML visual modeling tools can be used to easily link various stages of system development.
Ii. Unified Modeling Language-1
Unified Modeling Language (UML) is a common visual modeling language designed for object-oriented development.
UML uses a series of diagrams to describe the system
Describe system behavior requirements-use case diagram
Define the dictionary of the problem domain-use a class chart
How classes interact with objects-use the sequence diagram, collaboration diagram, state diagram, and activity diagram
Describe the software structure of the system-class diagram and component Diagram
Define the behavior of software in the system-adopt the sequence diagram, collaboration diagram, status diagram, and activity diagram
Describe the topology of the processors and devices that run the software-use a configuration diagram.
Ii. Unified Modeling Language-2
• These diagrams can be directly generated on a computer using visual modeling tools (such as Rational Rose and prosa), and the UML model can be converted into multiple programming language codes (C ++, visual c ++, Visual Basic, CORBA, Java, etc ).
• You can use a forward project to generate program source code and tables in the relational database from the model.
• Reverse engineering can be implemented using the reverse Generator tool to convert the source code of a program into a diagram of a UML model.
• This iterative system development method creates conditions for business process optimization and significantly improves system adaptability and maintainability.
Summary system implementation of management information systems: Implementation of physical systems (the sum of system activities such as ordering of computer systems and communication network system equipment, preparation of data centers, installation and debugging of equipment .) Programming (requires maintainability, reliability, comprehensibility, and efficiency. Structured Program Design features three basic logic structure programming: sequential structure, cyclic structure, and selection structure. Software development tools (such as spreadsheet software, database management system generation, software packages, visual programming tools, and computer-aided tools. Program and system debugging (including program debugging, debugging, general adjustment, special testing, and live testing. System Operation Management and Maintenance (system operation management refers to daily management, real-time recording and timely handling. Maintenance includes program maintenance, data file maintenance, and code maintenance .)
Chapter 9 Object-oriented System Development
Section 1 Basic object-oriented concepts
1. Basic concepts of objects-1
• In an object-oriented system, the problem object is a basic operating entity and is closed by a set of data and a group of operations applied to the data.
• Basic Elements of the object:
-Identifier: the object name, used to distinguish other objects in the problem domain;
-Data: Describes the storage or data structure of an object attribute, indicating a state of the object;
-Operation: the action of an object. Divided into operations on the object itself and operations applied to other objects;
-Interface: it refers to the set of operation names specified by the object to receive external messages.
• Object state machine Representation
Objects exist in the real world. It can be physical, such as a furniture or table, or conceptual, such as a development project. An object is an independent unit in the real world and has its own static features (described by attributes) and dynamic features (services ). For example, the static characteristics of a person include name, gender, and age. The dynamic characteristics include clothing, food, housing, and travel.
Message consumption
Send back message
Status Conversion
Connect
Port
Operation set
Status set
1. Basic concepts of objects-2

 

 

 

1. Basic concepts of objects-3
• Objects are the cornerstone of building and supporting the entire software system. Three main features of an object are:
-Module independence-dynamic connectivity-maintainability
• Object Recognition
-Objects are divided for different purposes of the system.
-The basic principle of object division is to find the commonalities of things in a large system and determine all common system components as an object.
Ii. Basic concepts of classes-1
• In the real world, there are many objects with similar internal states and external behaviors. A set of these objects is a class.
• Basic Elements of the composition class:
-Identifier: the name of the class to distinguish other classes;
-Inheritance Description: the name of the parent class inherited by the subclass and the inherited structure and functions;
-Data Structure: Describes the organizational structure of the data type;
-Operation: the specific implementation method of this type of general functions;
-Interface: a unified external communication protocol for other classes.
• Classes and objects
-The relationship between objects and classes is equivalent to the relationship between variables and types in general programming languages.
Objects with the same features and behaviors are combined to form a class. Class is a template of some objects, which abstracts the attributes and operations of all objects belonging to this class. Objects of a class are called instances of this class. The status of an object is included in its instance variables, that is, from the instance attributes, such as "Li Jie", "Wang Hui", and "Yang Fang", you can get the class "student ", these objects are called instances of this class.
Iii. Message and message transfer-1
• The object-oriented world is promoted through mutual cooperation between objects, and messages are the communication carriers between objects.
• A message is used to request an object to perform a certain processing or answer certain information, and is the link to the object. There are two types of messages in the object-oriented system: public messages and private messages.
• Messages have the following attributes:
-The same object can receive multiple messages in different forms to produce different responses.
-A message can be sent to different objects. The message interpretation is completed by the recipient object. Different objects can have different interpretations for messages of the same form.
-Unlike traditional program calls, an object can return corresponding response information or not, indicating that the message response is not required.
Iii. Message and message transfer-2
• Message transmission mechanism
-When a message is sent to an object, it contains information that requires the recipient to execute certain activities, and the object receiving the message is interpreted as a response, mutual cooperation between objects requires a mechanism to assist in the process. Such a mechanism is called "message transmission ".
• Message Mode and Method
-The message format is characterized by message pattern. A message mode defines a type of message.
-Message mode not only defines the messages that the object interface can accept, but also defines the inherent processing capability of the object, which is the unique information of the object interface. To use an object, you only need to understand its message mode.
-The processing capability of the message mode of an object is the so-called "method", which is a means to implement the specific functions of a message.
3. Message and message transmission-3
Transfer object
Recipient
Message consumption
<Operation name, parameter>
Connect
Port

 

Iv. Basic concepts of inheritance-1
• Inheritance refers to the mechanism or relationship between the capabilities and features of a class (that is, a subclass) that carries on another class (or a parent class.
• In summary, classes with inheritance relationships should have the following features:
-Classes share features (including data and program code sharing );
-There are minor differences or additions between classes (including non-shared program code and data );
-The class question has a hierarchical structure.
• Inheritance avoids data and operation redundancy caused by Closed System Classes and objects. Its most important advantage is its support for reuse.
Special classes inherit general classes
If several classes have common things (information structure and behavior), extract them and put them in a general class, and describe them separately in a special class, you can create special classes to inherit general classes. 6.10. Each special class can inherit the common from the general class, thus avoiding repetition.
Cars are specialized in automobiles. A car is limited to a car with multiple seats for manned use. In addition, you can also turn a car into a bus. It is a special type of car.
If a class needs to use features of multiple existing classes, it can be inherited from multiple classes, called multi-inheritance.
V. Object-oriented meaning-1
• Object-oriented = data abstraction + data abstraction type + Inheritance Mechanism
• Object-oriented is a cognitive methodology for understanding the objective world
-This recognition method regards the objective world as composed of many different objects. Each object has its own motion pattern and internal state, the interaction and communication between different objects constitute a complete objective world.
• Object-oriented is also a way of thinking to solve problems
-Modeled the objective world from the organizational structure, and abstracted the entire problem domain into a set of objects for mutual communication as the core or main body of requirement analysis and system design, the classification idea in the scientific methodology is referenced to combine similar or similar groups of objects and organize similar classes by various means to map the problem space to the solution space.
Section 2 principle of Object-oriented System Development
Process-oriented model process-oriented model is the most widely used and longest-history software model. It is the abstraction of the process in which software is regarded as a processing stream and defined as an algorithm composed of a series of steps. Each step is a process with a predefined input and a specific output. concatenating these steps can generate a reasonable and stable control flow throughout the entire program, finally, a simple architecture with a static structure is generated, and the process-oriented model focuses on establishing a processing stream that constitutes a solution to the problem. Data abstraction and data structure are developed according to the requirements of algorithm steps. It runs through the process and provides information about the operations required by the process. The state of the system is a set of global variables. These global variables save the state values and transfer them from one process to another.
A process-oriented structure of the draw program is given, and the basic algorithm of the program is also given. Many details are not given, but you can see the basic idea. In this example, the tasks of the system are arranged sequentially and can be arranged concurrently if necessary. When designing the system, first determine the task sequence and then define data that supports basic process operations.
In the process-oriented model, process abstraction is preferred. In the object-oriented model, the entity is the object of the problem universe. In the object-oriented model, the main entity in the problem universe of identification and modeling is used as the starting point of system development, mainly considering the behavior of objects rather than a series of actions that must be executed.
Objects in an object-oriented system are the synthesis of data abstraction and process abstraction. The state of the system is stored in the data storage defined by the core of each data abstraction. The control flow is included in the operations in various data abstractions. Unlike the process model, data is transmitted from one process to another, but the control flow is transmitted from one data abstraction to another through messages. The complete system architecture is more complex but flexible ,. The control flow is separated into blocks, so that complicated actions can be considered as the interaction between various parts.
The object-oriented architecture of the draw program. The arrows in the figure indicate messages from one object to another. It focuses on entities. There are physical entities such as the mouse, keyboard, and display, and conceptual entities such as events and shapes. No algorithm is provided here, because the algorithm is actually distributed to various entities.
Methodology of object-oriented system development-1
• From a macro perspective, the object-oriented system development methods include four stages: analysis, design, implementation, and operation and maintenance, following the ever-increasing lifecycle, as shown in Figure 8-4.
• At the micro level, the object-oriented system development method refers to identifying objects in each macro stage, determining object attributes, and defining object services, and how to determine the relationship between objects.
Object-oriented System Analysis-1
• Basic task of Object-Oriented Analysis:-identify and define a group of objects in the problem fields that act and interact according to the requirements of the system,
-Create a problem domain model based on these objects and their relationships.
• Basic Steps for Object-Oriented Analysis:-problem domain statement
-Recognize objects/classes
Criteria for Object Recognition: criteria for determining criteria for search
-Determining object attributes-determining object services-determining object/class relationships
Object-oriented System Design-1
• Object-Oriented Design Phase 1. Objects and classes identified in the configuration analysis phase; 2. Implement system functions;
3. Establish a system architecture. The specific task is:
• Add, merge, and modify object, and identify interface objects and control objects.
• Determine the relationships between object, interface object, and control object.
• Improve the structure of object classes and organize the system architecture.
• Basic Steps for Object-Oriented Design: 1. Identify interface objects and control objects
• Validation of interface object/class principles • Control Object Recognition
• Relationship between three types of objects 2. System Structure Design 3. Detailed design of each subsystem within the framework
Object-oriented System Design-2
• Detailed Design of subsystems within the framework
-Design of subsystems in the problematic domain (the main task is to improve the object attributes and operation form rules, including specifying attribute values and determining complex service algorithms, further standardize the object form description so that the object can be physically implemented ).
-Design of the Human-Computer Interaction subsystem (the interface object has been specified at the initial stage of the design. At this time, the overall strategy of the graphic user interface is determined.
-External interface subsystem design-Data Management Subsystem design-Task Management Subsystem Design
-Basic Object subsystem Design
Iii. object-oriented system implementation-1
• In the system implementation stage, we mainly choose encoding language, object-oriented application framework, object-oriented application programming, and information system application software platform.
Section 3 object-oriented system development tool-UML
• In principle, any method should consist of a modeling language and a modeling process. The modeling language provides the symbols used to represent the design (usually graphical symbols). the modeling process describes the steps required for design. UML unifies the basic concepts, terms, and graphical symbols of object-oriented modeling, and establishes a universal language for ease of communication.
The purpose of UML design is to: unify different modeling languages, unify the development stage, unify different software application domains, unify the internal structure, and coexist with a variety of different development processes.
I. Class Diagram and use case diagram-1
• Class Diagram-class diagram describes the static relationships between classes, such as associations, clustering/composition, and inheritance.
I. Class Diagram and use case diagram-2
• Use Cases-use cases are the symbols of the second generation of object-oriented technology,
-Describe system behavior or use cases from the user's point of view.
Ii. status chart and sequence diagram-1
• Status chart-an object is always in a specific State at any given time;
-A status chart includes a series of statuses and transition between statuses.
-The status chart legend is shown in the right figure.
Ii. status chart and Sequence Chart-2
• Sequence Chart
-The sequence diagram shows the time-based dynamic interaction between objects during system running, and focuses on the time sequence of message passing between objects.
-The horizontal axis of the sequence chart indicates different objects, and the vertical axis indicates time.
3. Activity diagram and collaboration diagram-1
• Activity diagram-it can be used to describe the action of an operation (class method;
-You can also describe the internal working process of Use Cases and objects.
3. Activity diagram and collaboration diagram-2
• Collaboration charts-collaboration charts are the interaction and link relationships between objects in the system to achieve the system's goal. -Unlike the sequence diagram, the collaboration diagram focuses on the static links between interaction objects.
Configuration diagram and component diagram-1
• Component diagram and configuration diagram-component diagram and configuration diagram are closely related to the entire computer system.
-The component diagram shows the software structure of the information system. The configuration diagram shows the physical architecture of the information system.
A summary of face-to-face analysis and image design systems: basic concepts of object-oriented (objects, classes, messages, and inheritance. Object-oriented is a cognitive methodology that understands the objective world and also a way of thinking to solve problems.) Object-oriented System Development Principles (object-oriented system development methodology. Analysis, design, and implementation of object-oriented systems .) Object-oriented System development tools-UML (class diagram, use case diagram, state diagram, sequence diagram, activity diagram, collaboration diagram, configuration diagram, and component diagram)