Lesson 3 - Systems - PDF

A. What is a System? The word System is derived from the Greek word Systema, which means an organized relationship between any set of components to achieve some common cause or objective. A system is “an orderly grouping of interdependent components linked together acco...

A. What is a System? The word System is derived from the Greek word Systema, which means an organized relationship between any set of components to achieve some common cause or objective. A system is “an orderly grouping of interdependent components linked together according to a plan to achieve a specific goal.” Constraints of a System A system must have three basic constraints − A system must have some structure and behavior which is designed to achieve a predefined objective. Interconnectivity and interdependence must exist among the system components. The objectives of the organization have a higher priority than the objectives of its subsystems. Properties of a System Organization Organization implies structure and order. It is the arrangement of components that helps to achieve predetermined objectives. Interaction It is defined by the manner in which the components operate with each other. For example, in an organization, purchasing department must interact with production department and payroll with personnel department. Interdependence Interdependence means how the components of a system depend on one another. For proper functioning, the components are coordinated and linked together according to a specified plan. The output of one subsystem is the required by other subsystem as input. Integration Integration is concerned with how a system components are connected together. It means that the parts of the system work together within the system even if each part performs a unique function. Central Objective The objective of system must be central. It may be real or stated. It is not uncommon for an organization to state an objective and operate to achieve another. The users must know the main objective of a computer application early in the analysis for a successful design and conversion. Elements of a System The following diagram shows the elements of a system −  Figure 1. Elements of a System Outputs and Inputs The main aim of a system is to produce an output which is useful for its user. Inputs are the information that enters into the system for processing. Output is the outcome of processing. Processor(s) The processor is the element of a system that involves the actual transformation of input into output. It is the operational component of a system. Processors may modify the input either totally or partially, depending on the output specification. As the output specifications change, so does the processing. In some cases, input is also modified to enable the processor for handling the transformation. Control The control element guides the system. It is the decision–making subsystem that controls the pattern of activities governing input, processing, and output. The behavior of a computer System is controlled by the Operating System and software. In order to keep system in balance, what and how much input is needed is determined by Output Specifications. Feedback Feedback provides the control in a dynamic system. Positive feedback is routine in nature that encourages the performance of the system. Negative feedback is informational in nature that provides the controller with information for action. Environment The environment is the “supersystem” within which an organization operates. It is the source of external elements that strike on the system. It determines how a system must function. For example, vendors and competitors of an organization's environment may provide constraints that affect the actual performance of the business. Boundaries and Interface A system should be defined by its boundaries. Boundaries are the limits that identify its components, processes, and interrelationship when it interfaces with another system. Each system has boundaries that determine its sphere of influence and control. The knowledge of the boundaries of a given system is crucial in determining the nature of its interface with other systems for successful design. B. System Models Schematic Models A schematic model is a 2-D chart that shows system elements and their linkages. Different arrows are used to show information flow, material flow, and information feedback. Flow System Models A flow system model shows the orderly flow of the material, energy, and information that hold the system together.  Program Evaluation and Review Technique (PERT), for example, is used to abstract a real world system in model form. Static System Models They represent one pair of relationships such as activity–time or cost–quantity. The Gantt chart, for example, gives a static picture of an activity-time relationship. Dynamic System Models Business organizations are dynamic systems. A dynamic model approximates the type of organization or application that analysts deal with. It shows an ongoing, constantly changing status of the system. It consists of − o Inputs that enter the system o The processor through which transformation takes place o The program(s) required for processing o The output(s) that result from processing. C. Categories of Information There are three categories of information related to managerial levels and the decision managers make. Figure 2. Categories of Information Strategic Information This information is required by topmost management for long range planning policies for next few years. For example, trends in revenues, financial investment, and human resources, and population growth. This type of information is achieved with the aid of Decision Support System (DSS). Managerial Information This type of Information is required by middle management for short and intermediate range planning which is in terms of months. For example, sales analysis, cash flow projection, and annual financial statements. It is achieved with the aid of Management Information Systems (MIS). Operational information  This type of information is required by low management for daily and short term planning to enforce day-to-day operational activities. For example, keeping employee attendance records, overdue purchase orders, and current stocks available. It is achieved with the aid of Data Processing Systems (DPS). D. System Design It is a process of planning a new business system or replacing an existing system by defining its components or modules to satisfy the specific requirements. Before planning, you need to understand the old system thoroughly and determine how computers can best be used in order to operate efficiently. System Design focuses on how to accomplish the objective of the system. System Analysis and Design (SAD) mainly focuses on − Systems Processes Technology E. Systems Development Life Cycle Systems Development Life Cycle (SDLC) is a process of understanding how information system (IS) can support business needs, designing the system, building it and delivering it to users. Many of the systems are not discarded are not delivered to the users considerably late, much costly than expected and have fewer features than originally formulated. Most of us would like to think that these problems occur only to other people or other organizations but they happen in most companies. An investment in an IS is like any other investments. The goal is not to acquire a tool because the tool is simply a means to an end; the goal is to enable the organization to perform work better so that it can earn greater profits or serve its constituents more effectively. An effective SDLC should result in a high quality system that meets customer expectations, reaches completion within time and cost evaluations, and works effectively and efficiently in the current and planned Information Technology infrastructure. SDLC is a conceptual model which includes policies and procedures for developing or altering systems throughout their life cycles. SDLC is used by analysts to develop an information system. SDLC includes the following activities − requirements design implementation testing deployment operations maintenance  Phases of SDLC Systems Development Life Cycle is a systematic approach which explicitly breaks down the work into phases that are required to implement either new or modified Information System. Figure 3. Phases of SDLC F. Systems Analyst The key person in implementing the SDLC is Systems Analyst (SA). He analyses the business situation, identifies opportunities for improvements and designs an information system to implement the improvements. SA is one of the most interesting, exciting and challenging jobs. As SA, you will work with a variety of people and learn how they conduct business. You will feel satisfaction of seeing the system you designed and developed and make a significant business impact while knowing that your unique skills helped make happens. The primary objective of SA is not to create a system but the main goal is to develop value for the organization which most companies means increasing profits. Many failed systems were abandoned because the analyst tried to build a wonderful system without clearly understanding how the system would support the organization’s goals, current business processes and other IS to provide value. SA Skills 1. Technical Skills a. Knowledge of computers and software. b. Keep abreast of modern development. c. Know of system design tools. d. Breadth knowledge about new technologies. 2. Business Skills a. Knowledge in the IT infrastructure b. Awareness in applying IT in the business situations c. Ensure that the IT delivers real business value 3. Analytical Skills a. System study and organizational knowledge b. Problem identification, problem analysis, and problem solving c. Sound common sense d. Ability to access trade-off e. Curiosity to learn about new organization 4. Interpersonal Skills a. Interface with users and programmer. b. Facilitate groups and lead smaller teams. c. Managing expectations. d. Good understanding, communication, selling and teaching abilities. e. Motivator having the confidence to solve queries. 5. Management Skills a. Understand users jargon and practices. b. Resource & project management. c. Change & risk management. d. Understand the management functions thoroughly. 6. Ethical Skills a. Deal fairly and ethically with other team members, managers and system’s users b. Deal with confidential information or if shared the system could not cause harm c. Maintain confidence and trust with all people SA Specialists 1. Business Analyst Focuses on the business issues surrounding the system. He helps to identify the business value that the system will create, develops ideas for improving the business  processes and helps design new business processes and policies. He will have business training and experience and knowledge if analysis and design. 2. System Analyst Focuses on the information systems (IS) issues surrounding the system. Helps ideas and suggestions for ways the IT can improve business processes, helps design new business processes, designs the IS and ensures that all IS standards are maintained. He must have trainings and experiences in analysis and design and in programming. 3. Infrastructure Analyst Focuses on technical issues surrounding the ways the system will interact with the organization’s technical infrastructure (hardware, software, networks and databases). He ensures the new IS conforms to organizational standards and helps to identify infrastructure that will be needed to support the system. He will have significant training and experience in networking, database administration and various hardware and software products. 4. Change Management Analyst Focuses on the people and management issues surrounding the system installation. He ensures that adequate documentation and support are available to users, provides user training on the new system and develops strategies to overcome resistance to change. He will have significant training and experience in organizational behaviour and specific expertise in change management. 5. Project Manager Often highly experienced SA. He ensures that the project is completed on time and within budget and that the system delivers the expected value to the organization. G. Overview of SDLC Planning Phase The fundamental process of understanding why an IS should be built and determine how the project team will go about building it. 1. Project Initialization The system’s business value to the organization is to identify how will it lower costs or increase revenues. Most ideas for new systems come from outside the IS area in the form of system request. System request presents a brief summary of a business need and it explains how a system that supports the need will create business value.IS department conducts feasibility study. a. Technical Feasibility (Can we build it?) b. Economic Feasibility (Will it provide business value?) c. Organizational feasibility (If we build it, will it be used?) 2. Project Management The project manager creates work plan, staff the project and puts techniques in place to help the project team control and direct the project through the entire SDLC. Analysis Phase The project team investigates any current system/s, identifies improvement opportunities and develops a concept for the new system. 1. Analysis Strategy Developed to guide the project team’s effort. It includes an analysis of the current system and its problems and of proposed ways to design a new system. 2. Requirements Gathering The analysis of the information leads to the development of a concept for a new system. The system concept is then used as a basis to develop a set of business analysis models that describe how the business will operate if the new system were developed. 3. System Proposal Presented to project sponsor and other key decision makers who will decide whether the project should continue to move forward Design Phase Decides how the system will operate in terms of the hardware, software and network infrastructure that will be in place; the user interface, forms and reports that will be used; and the specific programs, databases and files that will be needed. 1. Design Strategy Clarifies whether the system will be developed by the company’s own programmers, whether its development will be outsourced to another firm or whether the company will buy the existing software package. 2. Architecture Design Describes the hardware, software and network infrastructure that will be used. In most cases, the system will add to or change the infrastructure that already exists in the organization. The interface design specifies how the users will move through the system and the forms and reports that the system will be used. 3. Database and File Specifications Defines exactly what data will be stored and where they will be stored. 4. Program Design Defines the programs that need to be written and exactly what each program will do. Implementation Phase The system is actually built or purchased. It usually gets the most attention because for most systems it is the longest and most expensive single part of the development process. 1. Construction The system is built and tested to ensure that it performs as designed. Since the cost of fixing bugs can be immense, testing is one of the most critical steps in implementation. Most organizations spend more time and attention on testing than on writing the programs. 2. Installation The process by which the old system is turned off and the new one is turned on. It may include a cutover approach, a parallel conversion approach or a phased conversion strategy. One of the most important aspects of conversion is the development of a training plan to teach users how to use the new system and help manage the changes caused by the system. Maintenance Phase The system is basically implemented and used by the end users. The developers are conducting assessments of the actual utilization of the system. For any reasons, the end users may suggest and recommend changes, if any, in the installed system based on their experience in using and exploring it. 1. Support Plan Usually includes a formal or informal post-implementation review as well as systematic way for identifying major and minor changes needed for the system.