Computer Information Systems

An information system is a collection of people, hardware, software, data, and procedures that interact to generate information to support users in an organization.

Business Intelligence systems collect data that can be used by a company to help make business decisions.  Two common business intelligence systems are:

• Data Warehousing: a comprehensive collection of data about a company, its customers, and its business transactions.  This data is put into a form that makes it easy to perform complex queries.  Data warehouses can become very large.  For example Wal-Mart’s data warehouse can hold over 200 terabytes of data.
• Data mining: intelligent SW used to scan a data warehouse for patterns and relationships within the data that may not be apparent to management.  Another common use of data mining is customer profiling—which attempts to match customers with products they would be likely to purchase.

There are many types of information systems:

• Office systems:  HW and SW that increase productivity and enable communications
• Transaction processing systems: systems that enable businesses to perform routine transactions, such as order-entry, payroll, and accounting systems
• Management information systems: systems that provide managers and executives information they need to make business decisions.  MIS tools include data mining programs, Excel and various database management system programs
• Electronic data interchange (EDI) systems: systems that enable two different companies to exchange data electronically using a network
• ERP systems: a large, integrated application that is used by all of a company’s departments (manufacturing, sales, marketing, distribution, customer service, etc.)

Design and Manufacturing Systems include

• Computer-aided design (CAD): an application used to design products electronically
• Computer-aided manufacturing (CAM): used to help manage manufacturing operations and control the machinery used in those processes.
• Robotics: devices controlled by a person or computer that can react to sensory input

System development is the process of planning, building, and maintaining a system.  For most large and medium-sized companies, information system development is performed by the information technology (IT) or information systems (IS) department.  The person overseeing this department is typically the chief information officer (CIO).

Project managers are typically either a system analyst or senior programmer.  As the project lead, it is the responsibility of the project manager to plan, design, build and implement a system that meets time and cost budgets while also meeting the predetermined system requirements.

There are many different job functions within an IT department.  Pg 485 lists some typical IT job titles.  If you become a computer professional, you will likely hold one of these positions.

Outsourcing:If a company does not have enough people or employees with the right expertise, it often outsources.  Outsourcing is when a company contracts with an outside vendor for all or part of its IT functions. 

·         Companies outsource when they feel an outsourcing vendor can do the job cheaper and/or better than they can.

·         Reasons for the increased use of outsourcing by US firms include: high domestic wages/ overhead, low international wages/overhead, improved WAN technology, and flexible staffing options.

·         Disadvantages of outsourcing are potential conflict between employees and outsourcing personnel, time zone differences, cultural differences, language barriers, control and security, and less verbal communication.

There are two reasons why companies build new computer systems:

• To fix a problem
• To gain a strategic advantage over their competitors

The System Development Life Cycle (SDLC) is an organized sequence of steps used to develop an information system (pg 489).  It begins with the initial request for a new system and ends when the new system is fully operational and problem-free.  The six phases of the SDLC are:

• Preliminary Investigation
• Analysis
• Design
• Acquisition
• Implementation
• Maintenance

Mt. SAC offers a complete course (CISM 11)that explains the SDLC approach to system development.  The higher you advance within the computer industry, the more important it becomes to understand the SDLC—as it is used in many system development projects. 

A brief summary of the primary tasks that occur in each step of the SDLC is given below:

Preliminary Investigation: In this phase you

• define the problems with the current system (or define the business opportunity)
• develop possible solutions
• estimate the costs and benefits of the proposed solutions
• create a feasibility reportthat summarizes the data collected and gives a recommendation whether or not the project should move forward

Systems Analysis: In this phase you gather detailed information about the current system, analyze the collected data, and identify the requirements for the new system.

• Information about the current system is collected through interviews, questionnaires, organizational charts, and personal observation.
• Analysis tools such as entity-relationship diagrams, data flow diagrams, and use case diagrams are used to model the current system.
• System requirements (determining exactly what the new system must do) are gathered primarily through interviews with management, the IT staff, and end users.  Factors that must be considered when developing system requirements include input, output, processing, storage, and security.

System Design: In this phase:

• You specify the type of HW, SW, and network components that will be needed by the new system.
• New applications are designed using program flowcharts, pseudocode, structure charts, and/or data modeling.
• A network model indicating the locations of networking devices is created.
• The overall structure of the database is designed
• The design phase is where the project team designs a system to meet the system requirements identified in the analysis phase.
• A cost-benefit analysis is performed to determine if the project should move onto the acquisition phase

System Acquisition: In this phase:

• You decide whether to "make or buy" new software needed by the system.
• Request for proposals are made to vendors and vendor bids are evaluated.
• You purchase the new HW and/or software from the vendor(s) you have chosen

Implementation: In this phase:

• the new system is put into place using one of the following four system changeover methods: direct, parallel, phased, or pilot.
• new programs, data files, and databases are installed on the company’s production computers
• new HW is installed
• hardware and software testing is performed and problem areas corrected
• users are trained

System Maintenance: In this phase

• existing software is modified
• new hardware and software are purchased to update the system
• correcting any hardware and software problems that occur
• security policies and procedures are followed to keep the system secure
• user support is provided either in-house or through a third-party company

There are many approaches to systems development.  You are expected to know the traditional (SDLC) approach and the prototype approach.

• The traditional approach uses the six-step SDLC discussed above.  It is time consuming and can be quite costly, but is widely considered the best way to build an effective system.
• With prototyping, a small model of the overall system is built and presented to users for enhancements.  Based upon user’s input, the prototype model is developed further and brought back to the users for further enhancements.  This process continues until no more enhancements are needed.  At this point, the prototype becomes the finished system or the prototype becomes the model that is used to finish building the system.  The prototype approach is often used when the users are unsure of the system requirements or when the system must be developed very quickly.