In an organization, there are three different levels of management, each of which requires different types of information systems at each level. They are:
Top-level managers: these are the senior executives of an organization and are responsible for its overall management. Often referred to as strategic managers, focus on long-term issues and emphasize the survival, growth and overall effectiveness of the organization. They make strategic decisions like mergers and acquisitions, new product planning, capital investment etc.
Middle-level managers: they are called tactical managers and are responsible for translating the general goals and plans developed by strategic managers into more specific objectives and activities. The role of middle manager is to be an administrative controller who bridges the gap between higher and lower levels. They make tactical decisions which include pricing, capacity building, budget preparation, purchasing contracts etc.
Frontline/operative managers: they are called operational managers or low-level managers who supervise the operations of the organization. These managers often have titles such as supervisors or sales managers. They are directly involved with implementing the specific plans developed by middle managers. Some of the operational decisions include; production scheduling, sales, ordering and credit approval. The relationships among the three levels is presented below:
Decision types in an organization
An organization has a wide variety of decisions to make, ranging from highly structured decisions to unstructured decisions.
Structured decisions: is one that is made quite often, and one in which the decision is based directly on the inputs. With structured decisions, once you know the necessary information, you know the decision that needs to be made. For example, inventory reorder levels can be structured decisions. These decisions are routine, repetitive and well-defined decisions with clear procedures and rules. The information required for making these decisions is usually readily available and can often be processed using standard methods or automated systems. Example reordering inventory when it reaches a certain level, payroll processing, financial reporting.
Unstructured decisions: these decisions involve a lot of unknowns. They are generally based on criteria that are not well-defined, and information is more likely to be ambiguous or incomplete. The decision-maker may need to exercise some thoughtful judgment and creative thinking to reach a good solution.
More also, these decisions are novel, non-routine and complex with no clear procedure for making them. Example, setting a company’s strategic decisions, designing a new product and crisis management decisions.
Semi-structured decisions: are decisions which most of the factors needed for making the decision are known but human experience and other outside factors may still impact the decision. A good example of this decision is hiring process. Here, these decisions fall between structured and unstructured decision. They contain elements that are both clear and routine, as well as elements that require human judgment and analysis. In the hiring process, part of the decision is structured, like years of experience, education level etc., and part of the decision is based on human experience like social skills, problem-solving skills.
Types of Information System (IS)
Transaction Processing System (TPS)
This is a computerized system that enables operational level managers to carry out their day-to-day activities. These activities include records of daily transactions: sales, order entry, bill processing, shopping details, hotel reservation and inventory of goods and services rendered. Their activities involve:
The sales/marketing departments, there is daily processing of sales/orders
The account department, there is daily processing of accounts details such as the accounts receivable/payable
The manufacturing department, there is daily schedule of activities such as inventory control, production scheduling and details of manufactured goods
The human resource department, staff movement is processed, vacancies are advertised, applications are treated and interviews scheduled.
Management Information System (MIS)
This is an information system that generates reports and information to aid the management level, particularly the strategic managers and to a lesser extent the tactical managers, to make efficient and effective decisions. The system takes input from the TPS and generates reports that serve to plan, control, organize and direct activities of the firm. The system generates reports in a weekly, monthly or yearly basis but not daily as in TPS.
Some features of the TPS include:
It has analytical capability
It aids decision-making using past and present data
It supports structured and semi-structured decisions at operational and management levels
It has internal rather than external orientation
Decision Support System (DSS)
This is an information system that serves purely the tactical level management. It is particularly very suited for unique or rapidly changing semi-structured decisions that cannot be specified in advance as against MIS. Unlike the MIS, DSS has analytical capability to sieve through massive amount of data to generate information for decision makers. The system is generally user-friendly, very interactive and very ideal for constructing ‘what-if’ scenarios with a view to making the best decision per time. DSS supports complex decision-making and problem-solving.
The system analyzes large volumes of data to generate insights using sophisticated analytical models and data analysis tool. DSS supports complex decision-making and problem-solving. The system analyzes large volumes of data to generate insights using sophisticated analytical models and data analysis tools.
Features of DSS
It offers flexibility, adaptability and quick response
It operates with little or no assistance from IT professionals
It provides support for decisions and problems whose solutions cannot be specified in advance
It uses sophisticated analytical and modeling tools.
Executive Support System (ESS)
This is an information system that serves the strategic managers purely. It has less analytical capabilities than the DSS, but can solve a wide array of problems. The ESS can be considered a more interactive MIS and has capabilities for DSS and artificial intelligence combined to assist managers to identify and address problems and opportunities.
ESS helps the senior management to take strategic decisions. It gathers, analyzes and summarizes the internal and external information that is used in business processes. Example of ESS are; actions of various competitors, economic developments to support strategic planning.
Expert Systems (ES)
It is a system that provides an expert advice. It also acts as an expert consultant to users. They have specialized capabilities that enhance their analytical power and decision-making support.
In other words, expert systems are computer programs that mimic the decision-making abilities of a human expert in a particular domain or field. They are designed to solve complex problems and provide expert-level advice and guidance.
The examples of ESs are:
Credit application advisor
Process monitor
Diagnostic maintenance system
Investment analysis
Inventory management
Employee recruitment
Financial forecasting
Customer Relationship Management (CRM) Systems
The CRM manages a company’s interactions with current and potential customers. These systems help in tracking customer interactions, sales and support. Users of this information system include; sales, marketing and customer service departments.
Business Intelligence Systems (BI)
This is an information system that analyzes an organization’s raw data to provide insights for business decisions. These systems include data warehousing, data mining and reporting tools. Users of this information system include; managers and analysts who require data analysis.
MANAGEMENT INFORMATION SYSTEM
Concept of Information System
Information system is an organized combination of people, hardware, software, resources and communication networks. Information system is also a scientific study that covers strategic, management and operational activities. These three activities basically deal with the following activities:
Gathering of information
Processing of information
Storage of information
In other words, information system is a collection of hardware, software, data, people and processes that work together to transform raw data into useful information for the benefit of an organization.
Figure: components of IS
Components of Information System
Computer hardware:
These are physical equipment used for input, output and processing. The hardware structure depends upon the type and size of the organization. It consists of an input and an output device, operating system processor, and media devices. This also includes computer peripheral devices.
Computer software:
The application program used to control and coordinate the hardware components. It is used for analyzing and processing of the data. These programs include a set of instruction used for processing information. Software is further classified into three types: System Software, application software and procedures.
Databases
Data are the raw facts and figures that are unorganized that are later processed to generate information. Software are used for organizing and serving data to the user, managing physical storage of media and virtual resources. As the hardware can’t work without software the same as software needs data for processing. Data are managed using Database management system. Database software is used for efficient access for required data, and to manage knowledge bases.
Network:
Network resources refer to the telecommunication networks like the intranet, extranet and the internet. These resources facilitate the flow of information in the organization. Also telecommunication networks consist of computers, communications processors, and other devices interconnected by communications media and controlled by software.
Human resources:
It is associated with the manpower required to run and manage the system. People are the end user of the information system, end-user use information produced for their own purpose, the main purpose of the information system is to benefit the end user. The end user can be accountants, engineers, salespersons, customers, clerks, or managers etc. People are also responsible to develop and operate information systems. They include systems analysts, computer operators, programmers, and other clerical IS personnel, and managerial techniques.
Introduction to Management Information System (MIS)
Management information system is designed by an organization so that it can be used by the manager in performing the following functions; directing, planning, coordinating communicating and decision making.
MIS can also be said to be a structured system used within an organization to collect, process, store and disseminate information necessary for carrying out management functions.
Management concept
Is an art of getting things and activities done through people and with the people. It is normally performed by managers in an organization.
Operations performed by managers:
Plan by making strategies and goals
Organizing tasks: managers organize the tasks that are required to complete the work and group these tasks homogenously
Control performance: performance is controlled by managers by setting standards and must be made sure that standards are not deviated.
Information concept
Information is the data that has been processed, organized or structured in a way that provides meaning or value. It is an essential element in decision-making and communication.
One basic difference between data and information is that data is not used in decision making process, but information is used in the decision making process.
System concept
A system is a set of elements that work together to achieve a common objective. It helps in optimizing output of an organization. Subsystems are part of a larger system. Example, organization is a system, and departments like accounting department, human resources department, etc. are subsystems or the elements.
Role of MIS
Hardware administration:
Hardware administration involves managing and maintaining computer hardware and related infrastructure to ensure optimal performance and reliability example; monitoring and maintenance, repairs of faulty hardware devices, inventory management and security management.
Software development:
This is involving software engineers to develop needed software to be used in the organization. Here, IT experts in the organization may not likely have the requisite skill of software development. In this case, outsourcing will be applied.
End user support:
Ensuring every staff of the organization of the staff of the organization is aware of how to use systems, new and updated installed on the systems of the organization.
Others roles of the MIS are; data management, report generation and communication and collaboration.
MIS benefits
Provides better communication
Makes better use of resources
Improves customer services and relationships
Helps in recording and processing all business dealings and transactions
Provides easy access of information to managers and staff
It provides managers an interactive support in the decision making process.
Challenges of MIS
Data security: protecting sensitive information from unauthorized access and breached is one of the most challenging tasks of a MIS
System integration: ensuring seamless integration with existing systems and processes in another crucial challenge facing the use of the MIS
Cost: high initial set-up and ongoing maintenance costs can also be a barrier. Small organizations with low budget cannot afford
User training: ensuring that users are adequately trained to use the system effectively
Scalability: as organizations grow, their MIS must be able to scale accordingly. Ensuring the system can handle increased data volumes and more users without performance degradation can be challenging.
Interoperability: ensuring the MIS can effectively communicate and share data with other systems example, ERP, is essential for seamless operations.
Others are; obsolescence, user adoption, cultural barriers and data migration etc.
INFORMATION PROCESSING
Data and Information
Data is the record of the daily transactions of an organization example date, amount goods on invoices, detail of pay slips, number of hours of worked, number of vehicles produced or sold etc. it can be considered a series of digits, figures that represent an idea. They have no meaning on their own so they are raw-materials for data processing.
Information is an analyzed or processed data in a Meaningful form for decision making. They are related as follow:
20, 25, 15 Arrange Name Sex Age
Jane, Musa, Ibrahim Jane Female 20
Female, Male, Male Musa Male 25
Ibrahim Male 15
The term data and information are often used interchangeably on the account that information produced today can be fed back into the system at a later time for processing, thus, taking the place of data.
Data Processing Methods
Data processing can be defined as the methods and procedure through which data is converted to information. This is the manipulation of data, its retention and subsequent retrieval. Data processing methods can be categorized into three:
Manual data processing: this is form of data processing that involves no machine except a desk calculator, pencil, paper and typewriter.
Mechanical or electro-mechanical data processing: this is a form of data processing that involves the use of punched cards equipment.
Electronic data processing: this is the processing of data using electronic computers.
Data Processing Cycle
Data processing steps include: origination, input, processing, storage/output and distribution.
Origination: this is the collection or recording of original data (primary data) to a document called source document which forms the input data.
Input: this describes the data to be fed into the computer (initial data). It is prepared in a convenient or suitable form for processing. This form varies form one data processing device to another. An electromechanical device used the punched cards while an electric computer used magnetic tape, disk, terminals etc.
Processing: this is plan series of actions and operations performed on data using various data processing devices, to yield data in a more meaningful form called information.
Storage: this is the storage of processed data (information) secondary storage media for future purposes. The two arrows show the storage of information at one time and the information serving as input data at another time.
Output; this is the result of a processed data for the operator. This result could be distributed to the end-users of information or recirculated as input to the processing cycle.
Distribution: this is the distribution of the produced information to the appropriate quarters for decision making. The decision makes are the end users of information.
Data Processing Operations
On a daily basis, there are number of data processing operations carried out by every individual in the course of discharging one assignment or the other. The method of carrying out the operation depends on the method of processing employed. They include:
Recording: this involves the recording of data onto some forms or media. This is, expressing data in a form recognizable by a person or machine.
Duplicating: this is the reproduction of data onto many forms or documents. Backup copies are usually made to help users or operators recover form disaster.
Verifying; this is the process of checking the recorded data for possible errors. This is very important as it offers a means of ensuring the correctness of information before used.
Classifying: the process were by data is grouped, arranged or classified into a specific order. Classifying based on unique characteristic of the data items. Example is to classify the students in a class according to gender, age, state of origin, academic level etc.
Sorting; this is the arrangement in a particular order, either in an alphabetical order or numerically at ascending or descending order. That is to arrange classified data serially in alphabetic order last name, or ascending order of registration number. It help to locate records or data easily from a pool of other ones.
Merging: this is the combination of two or more sets of data into a single one in accordance with a specific rule. Reports in different files can be combined together as one.
Searching: this is the method of locating information in a table or file with reference to a specified field of each record called the key, if the file sorted according to the key, locating a particular record would be very easy.
Retrieval: is a method of finding, locating and extracting a specific data in a record. That is getting a record out of pool of records. To retrieve a record, it is faster if it is sorted the record searched, if found or located can be retrieved.
Calculating: this deals with performing arithmetic operations on arithmetic data. This is one operation that receives great attention. The bottom-line in any business is profit making and wrong calculation way change credit to debit.
Summarizing/Report writing: this is the method of reporting the result of an operation in a simple and straight form manner. That is presenting information in a contended or highlighted form. Appropriate reports are needed across the different levels of management and must be so produced.
Communication; is the transmitting information and data from one place to another. This operation takes different forms: email, voice mail and any other forms of communication.
Qualities/Values of Information
Relevance: information must be relevant to the purpose it is intended to serve. It must be related to the application area, otherwise it is irrelevant to the subject area and decision made based on this cannot be trusted neither can they be reliable.
Completeness: information should contain the last amount of details that is consistent with effective decision making, that is the inclusion of all the relevant information part information is useless (noise) unless it is complete or whole.
Accuracy: information should be sufficiently accurate for the purpose of effective decision making. It must be completely error-fore incorrect information could have damaging consequences.
Clarity: information must be clear to the user for it to be used appropriately. Clarity enhances usability, unclear information is redundant information as it cannot be comprehended nor disseminated.
Appropriateness: the quality of information required varies across the three levels of management (strategic, tactical and operational). The needed quality of information should be sent to the appropriate quarters or levels of management. While more details are needed are the lower level, less retails are required as you move up the pyramid of decisions.
Timeliness: information could be made available where needed a delay in data collection, processing and communication can lead to worth waste of paper. It has to be the right, most current and recent information to be useful.
Frequency: information should be produced at a frequency that is relative to the level of management at operational level-daily: tactical level-monthly; and strategic level-quarterly.
Source of Information
The source of information is from both within and outside an organization they are collected through:
An established collection or measurement system e.g measuring outputs, sales, costs, cash receipts, asset purchases, stock turnover etc.
Information communication between managers and staff e.g. briefings during a meeting.
Published article e.g the research and development work being done by other companies.
Published elicits/legislations
Questionnaires e.g carrying out researches to sample opinions of prospective customers etc.
Advantages of Using Computer
Data processing is virtually the same regardless of the methods of processing(manual, electro-mechanical, electronic). The importance/advantages of using the computer can be summarizes as follows:
Speed: the processing speed of a computers has made it used in information processing inevitable compared to the manual method. Its offer higher productivity when large volumes of job are involved.
Accuracy: computers are generally accurate where as human are prone to errors. There are three sources of errors: human errors (errors in data input), software errors (errors in programming) and hardware errors (system breakdown). All thing being equal the computer is still desirable.
Volume and capacity: human capability became inadequate with a large volume of jobs. The computer performs routine jobs quickly and efficiently.
Reliability: computer cannot be distracted and can function 24/7
Programmability: computer is well suited for automation of business and scientific applications through programming.
Disadvantages of Using a Computer
Intuition: under certain circumstances human intuition can be very useful and may improve the quality of decisions.
Improvision: human have the capability of reacting to unforeseen situations better than the computer.
Experience: despite recent development in artificial intelligence, human beings have proven to be better in decision making.
Innovation: human can be very creative and innovative.
Information Processing Organization
Centralized system
This is characterize by the use of large mainframe or mini computers that produce and large the information needs of an organization.in this management, the processing operation is performed by a single host, usually situated in the computer center and user have to go to the center in order to perform their processing needs, or at best, can hae access through remte terminals from various locations.
Decentralized system
Miniaturization in size of computer systems, brought about the development of mini computers and somewhat powerful processing capability, decentralized system emerged.
Organizations now provide each business unit with an independent computer system. Thus, each unit of an organization has its computer system for information processing and maintains its pertinent information independent of others with this arrangement isolated information is still a problem.
Distributed system
This concept is better explained as an offshoot of a decentralized system. That is a decentralized computing system with information sharing. When the various departments described in a decentralized system are link together, they form a distributed system, with each locality still maintaining its pertinent database. They can still enjoy inter-departmental communication and cooperation, thus enhancing data exchange. A distributed system may be formed by:
Expanding an existing centralized system by connecting intelligent remote terminals to enhance distributed processing capabilities.
Interconnecting independent decentralized computer.
Information Processing Techniques
Batch processing
Batch processing is a processing technique where by many individual jobs or tasks (batch of jobs) are executed by a single program loading. With this system, a single program is used to process many jobs sequentially without having to reload each of the jobs after the initial program loading. Batch processing is a method were a system process a group of tasks or data all at once, rather than one at a time. It is commonly used for large scale, repetitive tasks that don’t require immediate result.
An example is the payroll program that lone it is in operation process, the different employees’ pay-slips individually in a single continuous operation. There are variation in a batch processing. One is that a job may be so complex to be executed by a single pass and as such ay be executed or run-in phases with the result of a phase serving as input to the next phase. In this case, the number of program loading will depend solely on the number of phases but that does not change the overall processing techniques from batch processing, since in a phase several jobs are executed.
On-line Processing
On-line processing involves the connection of a computer with user oriented terminals. It is a real time interaction between users and the computer systems to input, process and receive immediate feedback on data. Terminals are under the control of CPU and hence are capable of interacting with the computer. Particularly, online processing has become a household technology used to denote direct connection to the CPU. On-line equipment operates at the same time and in cooperation with the computer to accomplish a task.
Examples of on-line system are:
A mouse attached to the computer for drawing various objects.
An attached plotter or printer to the computer to produce a graphical or textural output respectively.
A VDU with keyboard for interactive data entry into the computer.
Teleprocessing
Teleprocessing is a term that is generally used to refer to the various computer services using input and output terminals at remote locations form the computer. It refers to the use of tele communications equipment by a computer.
Tele processing has made it possible for people at different locations or part of world to attend conference without leaving their respective homes. That is, the technology allows their terminals to be looked together to the conference center where the seminar or conference is taking place with a special code.
Teleprocessing involves the following:
Conversational time sharing: where many users at remote locations through their terminals are put under illusion that they here the entire computer to themselves.
Enquiry servicing: where users can make an enquiry at remote locations about airline seat reservation and stock market quotations among other things.
Data acquisition: where users are able to gather information about the current state of an ongoing process in a timely fashion.
Message switching: where users are under the grise of having a personal switch board. This leads to lower cost of time concentration and communication by store and forward routing of messages.
Real- time Processing
Real-time describes the processing situation where the computer is able to respond to urgent signals realistic in human reaction time, to simulate in real time means to simulate at exactly the real-world time rate. Real time system is used to control an ongoing process and its output made available urgently to effect necessary changes for effective control. An example is the air seat reservation, chemical process control and military warfare.
Time-sharing System
Time-sharing system, from the name implies sharing of the computer time among many users. This term is associated with a computer in a multi-access mode or simultaneous utilization of the computer from multiple terminals.
Let us considered a centralized system having (N) number of users. The computer time is shared among the various users connected to it and giving each of them the impression that the computer is dedicated to his job, but in actual sense the computer services each of them in rotation. This is made possible by the fact that the computer spends a fraction of a second at each work station, does as much work at the apportioned time, shifts to the next station, on and on vatic everyone is being serviced. This system has two basic functions:
To handle communication needs by various users and
To execute the users program
The system is equipped with a clock, which govern the duration of stay at each location. It is also worth nothing that in a time-sharing system all terminals (users) that can be serviced are limited to the number that the communication controller can handle and the central processing speed.
Multiprogramming System
Multiprogramming is a computer technology that refers to concurrent processing of more than one job. In a system having only one processor, multiprogramming is possible by performing an interleave operation of more than one job resident in the memory and whose processor time requirements are diverse. That is, when the processor is bury performing computation on one job, the offer job may be doing input/output (I/O) operations, thus enhancing system throughout and reducing the processor idle time.
Multiprogramming enhances:
Sharing if the processor time
Sharing of the main store (2 or more jobs reside there)
Potential sharing of other resources.
Therefore, multiprogramming attempts to maximize the efficiency of the computer by keeping busy all the components of the computer.
Multiprocessing System
A multiprocessing system is a computer system that has more than one processor, thus enabling it to process many jobs simultaneously. A multi-processing system houses several jobs in the main memory of the computer just like in multiprogramming but differs from multiprogramming because it processes jobs simultaneously rather than overlapping (interleaving) I/O and computing operation. Therefore, multiprocessing fosters throughput, reliability, parallelism and economy of scale.
Multitasking System
Multitasking stands for multi programming on single user systems (PC) it afford one person the opportunity of running more than one program concurrently on a single PC, MS windows is a multi-tasking operation system, which allows more than one program to be run concurrently. This is while typing a document in word, access or excel could be used to search some records of client simultaneously.
FILE ORGANIZATION, DATABASES AND DATA WAREHOUSE.
Bits: an acronym for binary digits, 0’s and 1’s which the computer language.
Character: a collection of related bits. It is also said to be a basic unit of information that represents a letter, number, symbol, or control code. It can be a single alphanumeric character like “A” or a special character like “$” or “&”.
Record: A combination of related characters e.g. Name gender etc.
File: A combination of related records with same fields.
Database: this is an integrated collection of related files about a firm, serving as a pool of information for many users. The person who creates and maintains the database is called Database Administrator (DBA). Example, consider a file of employee records containing: Name, Gender, State, and Department.
S/N
NAME
GENDER
STATE
DEPARTMENT
1
Ayodele
M
Kogi
Registry
2
Funmilayo
F
Ogun
Computer
3
Ahmad
M
Kwara
Administration
Software Development Lifecycle (SDLC)
The SDLC refers to a set of activities that constitute the phases of development involved in producing a computerized information system (CIS). That is, the developmental phases involved in producing a computer based system. Generally, the term ‘lifecycle’ is used to cover the birth, life and death of an organism or ecosystem. The SDLC is no exception. A computer system will come into existence, have an interesting life and then dies. In essence, a system can be developed (birth), put to use (live), and becomes obsolete with time and hence replaced (death).
The activities of the lifecycle are constituted into phases of information system development (ISD). They include:
Scope and objectives
Feasibility analysis
Systems design
System implementation and conversion
Post implementation review and maintenance
Scope and objectives
Systems analysis and objectives and design is carried out by a project team, which includes owners, users, designers, builders and analysts. The system owners meet with the project team to describe in clear terms the following issues:
What is desired?
What area of business to investigate (scope)?
What area of system to improve?
In this phase, details about budget, time and available resources are discussed. These details are contained in what is referred to as the “project’s terms of reference”. That is, the scope is well stated and the objectives are clearly defined as they help to define in clear terms the actual task to be done by the team.
Feasibility study
This is a study carried out prior to a development project to ascertain that the proposed system is feasible and can serve the intended purpose. That is, following the terms of reference in the scope and objectives, an initial investigation of the system is undertaken to find out the details of what is required, its possibility given the available resources viz; time, finance, manpower and technology. The findings are contained in a report called feasibility report.
The purpose of feasibility study is to investigate the present system and evaluate the possible application of a revised or new system. After this, a system is selected tentatively, its cost and effectiveness evaluated, as well as its impact on existing personnel, before it is finally determined if a new or retrained personnel is needed for the system.
It is however necessary to conduct series of tests about each of the alternative systems to establish clearly the benefits and liabilities. The analyst should determine if the solution is feasible or achievable, given the available resources; and determine the technical feasibility and economic feasibility.
System analysis
Is the process of studying the network of interactions within an organization with a view to assisting in the development of new or improved methods of performing the necessary work. System analysis involves the following steps:
Problem definition and classification
Data collection and analysis
Analysis of system’s alternatives
In problem definition and classification, the system’s analyst is charged by the management of an organization to assess the nature of the problem, the possible causes(s) and proffer an effective solution. In this, problem definition and classification requires considerable amount of data to be collected and analyzed to give the analyst a direction of search. Once the problem has been clearly defined, the analyst will have a clear picture and a statement of objective for the remainder of the project.
Data collection and analysis is the next step to collect facts (data) regarding the problem, having clearly defined the problem. This activity is called data collection and data analysis. This analyst will collect the relevant data to the problem; analyze it critically in order to find a lasting solution to the problem. Tools and techniques for data collection and analysis include; system interview, standard flowchart, decision table and questionnaire.
While in analysis of system’s alternatives, the complexity of most systems has made it practically impossible to evolve a solution that is ideal to a major problem. It is pertinent to consider the merits and demerits of several alternatives before selecting anyone as the best. Usually, it is the responsibility of the management to select any alternative considered best among all other options.
System design
This is the development of the actual mechanics for a workable system. At this stage, the analyst focuses attention on the ways and manner in which jobs would be processed on the system. He develop[s specifications for the system’s inputs, outputs and information base. The product of the design phase is a set of operating procedures, computer programs and hardware specifications. Program development comes in after having developed the system on paper (system flowchart), the programmer then takes over to develop the main logic needed to actualize the proposed system. The programmer develops program flowchart, decides on the choice of the programming language, followed by the actual coding and testing of the program.
Design tools for system design include:
Programming: involves translating the design specifications into program codes. This includes design documentations, transmission and report layouts and the specifications for each program.
Prototype system development: pilot or prototype system development involves developing a model for the proposed system, having all its characteristics. In short, it is an abstraction of the real system which can be subjected to series of tests in order to predict the behavior of the proposed system in real life.
System implementation and conversion
Putting a new system in operation is usually a very complicated process due to the fact that the old system is still in use. In some cases, implementation may involve entirely new equipment; that is, changing from a manual system to an automated one or just a change in capacity of the system. Under system implementation, testing of the new or modified is very important. Testing comes in these three ways:
Unit testing: it involves testing each program unit with a view to detecting errors at the elemental units of the system. If each program unit is error-free, then the whole system has a high degree of probability of being free of errors.
System testing: this involves testing the functionality of the entire system. It is one thing for the for the individual units that make the system to function well, it is another that after integration, the whole system will function together as a unit.
Acceptance: this is a final certification that the system is ready for installation and implementation. The test is performed by users and technical staff, and reviewed by management.
Conversion: is the method of changing from one system to another, particularly a new one, is known as conversion. There are several commonly used methods of changing from the old system to the new. These methods are:
Parallel method
Dual method
Inventory method
Pilot method
Parallel method
This conversion method involves simultaneous operation of both the old and the new system until the new system is certified efficient.
Dual or phase method
This involves gradual phasing out the old system for a new one. Hence, it is known as “gradual change method” or “phasing method”. The cost associated with this is not very high since there is little or no duplication of work, rather, part of the job is done on old while the remaining is done on the new system.
Inventory method
This is called “Direct” or “Crash” method. It requires one-time conversion from old to new. This approach is carried out on non-business days (weekends). Critics of this method argued that:
It is clear, quick and reasonably inexpensive
It is risky and potentially suicidal
Pilot method
This method involves implementing a small portion of the new system either in parallel or dual method, while a major portion is processed on the old system.
Post-implementation review and maintenance
There is need for post-installation process whereby the analyst examines the performance of the system, compares his findings with the initial expectations and makes recommendations based on these. In post-implementation process, usually a task force is set up to conduct post-implementation to ascertain the operations and effective performance of the implemented system.
