CS507 Information Systems Solved Subjective Short Questions Answers from Text Book (chapter 4 - 10)

[+ M.Tariq Malik]

CS507 Information Systems Solved Subjective Short Questions Answers from Text Book (chapter 4 - 10)

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CS507 Solved Subjective Questions from Text Book (chapter 4 - 10))

Chapter 4

1.  Describe the key ideas in the technical-rational school of management.  What are the five functions of managers described in the classical model?

 

The organization is seen as a closed, mechanical system.  The emphasis is on design of a system and managing for efficiency.  The five functions of managers are planning, organizing, coordinating, deciding, and controlling.

2.  Describe the key ideas in the behavioral perspective on management.  What characteristics of modern managers does the behavioral school emphasize?

 

The key ideas are that organizations are seen as open, biological organisms like a cell, or animal.  The organization’s survival depends on its ability to adapt to the environment and to ensure that all the parts are working together.  As part of the effort to be successful, the members of the organization are satisfied and functioning well.  The characteristics that are emphasized by the behavioral school are highly fragmented activities, changing activities rapidly, spending time pursuing personal goals, and shying away from sweeping policy decisions.

3. What specific managerial roles can information systems support?  Where are information systems particularly strong in supporting managers, and where are they weak?

 

They can support the liaison roles of managers through e-mail, and the information roles of nerve center, disseminator, spokesman, and resource allocator.  They are probably strongest at the nerve center, resource allocator, and spokesman roles.  They are particularly weak at figurehead, leader, disturbance handler, and negotiator roles.

4.  What did Wrapp and Kotter discover about the way managers make decisions and get things done?  How do these findings compare with those of the classical model?

 

Wrapp closely examined the characteristics of managerial decisions. He found that good managers rarely make forthright policy decisions, preferring to devote more time and energy to operational decisions. Managers tended not to set overall organizational goals but instead provided the organization with a general sense of direction. In this manner mangers maintain visibility without being forced into a policy straightjacket.

Kotter's research describes how managers get their work done.  They devote considerable time to establishing personal agendas and short and long-term goals. They spend a great deal of time building interpersonal networks throughout the organization, cultivating personal contacts and relationships.  Managers then use these personal networks to execute their personal agendas.  Computerized information systems that facilitate communication and networking help support these activities.  Especially useful are electronic mail systems, voice messaging, and teleconferencing facilities.  The chapter also notes the value of systems that provide instant access to management-level information on sales performance and external data such as currency and commodity values.  Contrary to the classical description, even senior managers shied away from grand sweeping decisions in favor of "muddling through."  Contemporary managers prefer to implement plans piece by piece without drawing attention to an explicit comprehensive design.

5.  Describe the key ideas of the cognitive perspective on management. 

 

The organization is a knowing, sentient organism.  Organizations seek to make sense out of their environments and can “learn and “know.”  The efficiency and effectiveness of the organization depend on its ability to be correct in its learning and judgments, as well as the organization’s ability to gather and disseminate information.  The manager’s role is to use his or her ability to properly define the situation of the organization and to build the information and knowledge infrastructure of the organization. 

 

6.  Define structured and unstructured decisions.  Give three examples of each.

 

      Unstructured decisions are non-routine decisions in which the decision maker must provide judgment and evaluations for which there is no standard procedure.  Examples are: Deciding to start a new division,  a new marketing campaign, a decision to invest in a country. 

 

Structured decisions are repetitive and routine with standard procedures for solutions.  Examples would be:  product mix, plant scheduling, facility layout.

 

7. What are the four kinds of computer-based information systems that support decisions?

 

The four kinds of computer-based information systems that support decisions (from lowest to highest) are:

Transaction processing systems (TPS

Management information systems (MIS)

Decision support systems (DSS)

Executive support systems (ESS)

 

8. What are the four stages of decision making described by Simon? 

 

Simon's four stages of decision making are:

• Intelligence: identification of problems, where and why. Information systems can deliver a wide variety of detailed information.
• Design: designing a set of multiple solutions for problems. Small DSS systems operate on simple models that can be developed quickly and operated with little data to support the designers.
• Choice: choosing among alternatives. Larger DSS can be used to develop more extensive data on a variety of alternatives and use complex analytic models  to account for all of the consequences.
• Implementation: monitoring the progress of a specific solution. Reporting systems can be used to obtain information on specific solutions.

 

9.  Describe each of the four individual models of decision making.  What is the name, basic concept, and dominant inference pattern of each?  How would the design of information systems be affected by the model of decision making employed?

 

• Rational model—an individual has goals or objectives that have a payoff function allowing the ranking of all possible alternative actions by the action’s additional gain.  The individual chooses the highest alternative.  The dominant inference pattern is rational ranking of possible choices according to some objective.
• Bounded Rationality and Satisficing—individuals are not assumed to be able to comprehend and rank all alternatives.  Instead, individuals take the first alternative that moves them toward their goals.  Individuals do not make actions that are too different from what they are doing currently.  The inference pattern is still “hill climbing” moving toward a goal.
• Muddling Through—individuals make limited successive comparisons with trade-offs among values.  The dominant inference pattern is limited comparisons, incremental decision making, with agreement among other people as the final test of the decision.

 

Implications for information system design are that decision-making is a very complex process, even when a rational model is assumed. Decision situations are high variable, depending on individual frame of reference, nature of goals and types of decision-makers. Information systems are more useful for supporting the decision-making process than for making decisions in place of people. Therefore, IS design should be flexible, with many options for handling data, evaluating information and supporting a variety of decision styles and skills. IS should, wherever appropriate, use powerful models for evaluating data with the ability to track many alternatives and consequences.

10. Describe each of the four organizational choice models.  How would the design of systems be affected by the choice of model employed?

 

The subsection of 4.4, Organizational Models of Decision Making summarizes the four “models of organizational decision making.”  The four models are:

1)   Rational model - assumes that human and organizational behavior is based in value-maximizing calculation within certain constraints (profit maximization or expected utility maximization in decision theory).

2)   Bureaucratic models - the most important goal is the preservation of the organization, with reduction of uncertainty a major goal.  Organizations following this model change incrementally.

3)   Political model - what occurs in the organization is the result of power relations and political interest groups.

4)   Garbage can model - assumes that organizations are not rational, and decisions are accidents.

 

11. How has the management process changed? What is the role played by information technology?

 

Managers now have to manage entire processes as in the Lantech Window on Organization in Chapter 3.  Managers have to treat the knowledge and core competencies of the organization as the key assets.  Further, managers have to adapt to current regulatory rules and social mores.  Managers are responsible for enabling employees to meet their goals and the organization’s.

Information technology allows the reengineering of business processes and management of workflow.  Information systems allow managers to share information more easily and learn the state of the world more easily.

 

Chapter 8

1. Why is file management important for overall system performance?

 

Information cannot be used effectively if it is stored in a unorganized, inflexible manner. Without proper file management, it may be difficult and even impossible to extract information from an automated system. File management must also be flexible enough to accommodate new pieces of information or to combine different pieces of information in changing ways. When computer files are poorly managed, poor performance, high costs and minimal flexibility will result.

2. Describe how indexes and key fields enable a program to access specific records in a file.

 

An index, like an index in a book, provides a means of finding a specific record's storage location. The index is a list of the key field of each record and the address where the record is stored.

Key fields provide a means of uniquely identifying records, such as a social security number or a product number. Being unique, the key field is the key to an index table which associates the storage address of each record with its key.

3. Define and describe the indexed sequential access method and the direct file access method.

 

The indexed sequential access method (ISAM) is a way of storing data records on a physical storage device in sequential order for sequential processing (such as in payroll applications). However, ISAM also allows any specific record to be directly accessed without searching through the file sequentially by using the record's key field to find its storage address in an index.

The direct file access method does not store the records in sequential order, as with ISAM. It uses a key field to determine the location of each record. However, rather than carrying that location in an index, the location is calculated each time using an algorithm that translates the key field directly into the record's physical storage address.

4. List and describe some of the problems of the traditional file environment.

 

Data redundancy is the presence of duplicate data in multiple data files. In this situation confusion results because the data can have different meanings in different files. Program-data dependence is the tight relationship between data stored in files and the specific programs required to update and maintain those files. This dependency is very inefficient, resulting in the need to make changes in many programs when a common piece of data--such as the zip code size--changes. Lack of flexibility refers to the fact that it is very difficult to create new reports from the data when needed. Ad hoc reports are impossible; a new report could require several weeks work by more than one programmer and the creation of intermediate files to combine data from disparate files. Poor security is a problem resulting from the lack of control over the data because it is so widespread. Sharing of data can be virtually impossible because it is distributed into so many different files around the organization.

5. Define a database and a database management system.

 

A database is a collection of data organized to service many applications efficiently by centralizing the data and minimizing redundant data. A database management system is special software that permits an organization to centralize data, manage it efficiently, and provide access to the stored data by application programs.

6. Name and briefly describe the three components of a DBMS.

 

The three components of a database management system (DBMS) are:

• The data definition language which is the formal language used by programmers to specify the content and structure of the database.
• The data manipulation language, which is used to manipulate the data in the database. It contains commands that permit end-users and programming specialists to extract data from the database to satisfy information requests and develop applications.
• The data dictionary, which is an automated or manual file that stores definitions of data elements and data characteristics such as usage, physical representation, ownership and security.

 

7. What is the difference between a logical and a physical view of data?

 

A logical view of data is the way data is perceived by end users or business specialists. A physical view of data is the way the data are actually organized and structured on physical storage media.

8. List some of the benefits of a DBMS.

 

• Complexity of the information system environment can be reduced.
• Data redundancy and inconsistency can be reduced.
• Data confusion can be eliminated.
• Program-data dependency can be reduced.
• Program development and maintenance costs can be radically reduced.
• Flexibility of information systems can be greatly enhanced.
• Access and availability of information can be increased.

 

9. Describe the three principal database models and the advantages and disadvantages of each.

 

The hierarchical database model stores data logically in a vertical hierarchy resembling a tree-like structure. An upper record is connected logically to a lower record in a parent-child relationship. A parent segment can have more than one child but a child can only have one parent. Hierarchical DBMS are good for treating one-to-many relationships. They can store large numbers of segments and process information efficiently, but they can only deliver information if a request follows the linkages of the hierarchy. Their disadvantages are their low user-friendliness, inflexibility and complexity of programming. They are good for high volume rapid response systems, such as airline reservation systems.

The network model stores data logically in a structure that permits many-to-many relationships. Through extensive use of pointers, a child segment can have more than one parent. Network DBMS reduce redundancy and, like hierarchical databases, they process information efficiently. However, they too are inflexible and are very complex to maintain and program.

The relational structure overcomes many of the limitations of these other structures. Data are organized into two-dimensional tables, each of which can be considered a file. The relational model can relate any piece of information in one file to any piece in another file as long as the two tables share a common data element (such as an employee number). Because relational DBMS can easily combine information from different sources, they are more flexible than the other DBMS structures. Access paths to data are not pre-specified, so that they can easily respond to ad-hoc inquiries with less extensive programming. The main problem with relational DBMS is poor processing efficiency. Response time can be very slow if large numbers of accesses to data are required to select, join and extract data from tables. Developments in relational technology are starting to overcome this problem, such as indexing.

10. What is normalization? How is it related to the features of a will-designed relational database. 

 

Normalization is to streamline the database design to remove redundant data such as repeating groups.  A database which is not normalized will have inefficient queries and will delete information when it should not or update only part of the information on a person. 

11. What is a distributed database, and how does it differ from distributed data processing?

 

A distributed database is one that is partitioned, or distributed among more than one physical location. Parts of the database are stored in one location and other parts are stored and maintained in other locations. One main central database can be partitioned into multiple local databases. These databases can be updated locally and later justified with the central database. Alternatively, the central database can be duplicated at various remote locations. Another possibility is to maintain a central index and have complete records stored at local levels.

Distributed data processing means using microcomputers, minicomputers and small mainframes at remote locations to process information in a central database rather than relying entirely on a central mainframe. However, unless the database itself is distributed, the data are still stored in one central location.

12. What are object-oriented, hypermedia and multidimensional databases? How do they differ from a traditional database?

 

Traditional databases store only homogeneous data that can be easily structured into predefined data fields and records. They are not well suited for handling other types of data such as procedures or graphics. Object-oriented databases store data and procedures together as objects. Hypermedia databases store chunks of information in linked nodes. These nodes can contain text, graphics, sound, full-motion video or executable computer programs. These databases will be less structured than in traditional DBMS and contain a wider array of data. The nodes of a hypermedia database can be linked in any kind of relationship established by the author.

13. Describe the capabilities of on-line analytical processing (OLAP) and multidimensional data analysis.

 

On-line analytical processing and multidimensional data analysis allow the analysis of large volumes of data from many perspectives, for example, sales by item by department by store by region, in order to find patterns in the data.  Such patterns are difficult to find with normal database methods, which is why a data warehouse and data mining are usually parts of  OLAP.

14. What is a data warehouse?  How can it benefit organizations?

 

A data warehouse is a database with archival, querying and data exploring tools (i.e., statistical tools) for storing historical and current data of potential interest to managers throughout the organization and from external sources (e.g. competitor sales or market share). The data originate in many of the operational areas and are copied into the data warehouse as often as needed.  Date warehouses support looking at the data of the organization through many views or directions.  To complete the Vegamatic (TM) analogy used earlier, a data warehouse allows managers to look at products by customer by year by salesperson -- different “slices” of the data.  Normal operational databases don’t permit such different views or slices of the data.

15. What are the four key elements of a database environment? Describe each briefly.

 

The critical elements in a successful database environment are:

• Data administration: the policies, procedures and tools for managing and planning for information as a corporate resource.
• A data planning and modeling methodology from an enterprise-wide perspective (for the entire organization).
• Users: end users have a wider role with DBMS than in traditional systems and so must be trained.
• Database technology and management: DBMS software maintained by the firm's database administration group.

 

16. Describe and briefly comment on the major management challenges in building a database environment.

 

Answers will vary with individual students. Some of the major management challenges in building a database environment are:

• Organizational obstacles to a database environment: Implementing a database requires widespread organizational change. Individuals and interest groups who do not want to relinquish control over information or share data with other groups in the organization can offer political resistance.
• Cost-benefit considerations: Implementation of a database environment entails considerable cost and effort, and most benefits are long-term. Many of the benefits of DBMS are also intangible. Management may resist moving to a database environment because the benefits appear overshadowed by short-term costs.
• Organizational placement of data management function: Often a low-level technical group is charged with implementing databases rather than assigning this mission to a group with strong senior management and end-user backing high in the organization. The result of low-level placement can be a piecemeal approach to database use and a failure to address the key organizational issues.

 

Chapter 9

1.         What is the significance of telecommunications deregulation for managers and organizations?

 

Deregulation of telecommunications means that organizations do not need to rely on the telephone com­pany for telecommunications services and devices. Organizations can choose from many different com­panies and services selling telecommunications services and equipment. To use telecommunications wisely, organizations must develop expertise in telecommunications and may need to employ their own telecommunications specialists. Managers must know alternative telecommunications technologies and systems and the costs, benefits and capabilities of various technologies, as well as a method for determining the organization's telecommunications requirements.

2.         What is a telecommunications system? What are the principal functions of all telecommunications systems?

 

A telecommunications system is a collection of compatible hardware and software arranged to communicate information--text, graphic images, voice or video--from one location to another. The principal functions of all telecommunications systems are:

• Transmission of information.
• Establishing an interface between sender and receiver.
• Routing messages along the most efficient path.
• Processing information to get the right message to the right receiver.
• Checking and editing transmitted information for errors and formats.
• Converting messages from the speeds and codes of one device to those of   another.
• Controlling the flow of information, routing messages and maintaining overall network structure.

 

3.         Name and briefly describe each of the components of a telecommunications system.

 

The components of a telecommunications system are:

• Computers: to process information.
• Terminals and other input/output devices: to send or receive data.
• Communications channels (using such media as telephone lines, fiber optic cables, coaxial cables, wireless transmission): to link sending and receiving devices in networks.
• Communications processors (such as modems, multiplexers, front-end processors): to provide support functions for data transmission.
• Communications software: to control input and output activities and to manage other functions of the communications network.

 

4.         Distinguish between an analog and a digital signal.

 

An analog signal is represented by a continuous wave which passes through a communications medium. A digital signal consists of separate discrete waves.

 

5.         Name the different types of telecommunications transmission media and compare them in terms of speed and cost.

 

Medium                                    Speed                                       Cost

Twisted wire                             300 BPS--     10 MBPS             Low

Microwave                               256 KBPS--100 MBPS

Satellite                                     256 KBPS--100 MBPS

Coaxial cable                              56 KBPS--200 MBPS

Fiber optic cable                        500 KBPS--  10 GBPS              High

 

6.         What is the relationship between bandwidth and the transmission capacity of a channel?

 

Bandwidth is the range of frequency (difference between the highest frequency and the lowest frequency) that can be accommodated on a particular telecommunications medium. The greater the range of frequencies that the telecommunications transmission medium can accommodate, the greater the medium's telecommunications transmission capacity.

7.         What is the difference between synchronous and asynchronous transmission? Between half-duplex, du­plex and simplex transmission?

 

Asynchronous transmission transmits one character or byte at a time over a line. Each string of bits com­prising a character is framed by control bits. Synchronous transmission sends characters in blocks, framed by header and trailer bytes called flags. Synchronous transmission is used for transmitting large volumes of data at high speeds because groups of characters can be transmitted more rapidly as blocks with no start and stop bits between characters.

In simplex transmission, data must always travel in only one direction. Half-duplex transmission allows two-way flow of data, but data can only travel in one direction at a time. Full-duplex transmission can send data in both directions simultaneously.

8.         Name and briefly describe the different kinds of communications processors.

 

• A front-end processor is a small computer (or programmable minicomputer) dedicated to communications management. It is attached to the main or host computer in a computer system. It performs such special communications processing as error control, formatting, editing, controlling and routing, and speed and signal conversion.
• A concentrator is a programmable telecommunications computer that collects and temporarily stores messages from terminals to send them in economical batches.
• A controller (often a specialized minicomputer) supervises communications traffic between the CPU and peripheral devices such as terminals and printers, managing messages from these devices and communicating them to the CPU and routing output from the CPU to the appropriate peripheral device.
• A multiplexer enables a single communications channel to carry data transmissions from multiple sources simultaneously. It divides up the telecommunications channel into multiple channels so that it can be shared by multiple transmission devices.
• Modems translate a computer's digital signal into an analog form for transmission over ordinary telephone lines, and it translates the analog signal back into digital form for reception by a computer at the other end.

 

9.         Name and briefly describe the three principal network topologies.

 

1)   Star network - involves a central host computer connected to a number of smaller computers or termi­nals. All communication between points in the network must pass through the host computer.

2)   Bus network - links a number of computers by a single loop circuit made of twisted wire, cable or opti­cal fiber. All messages are transmitted to the entire network and can travel in both directions along the cable. There is no need to have a host computer controlling the network.

3)   Ring network - similar to a bus network except that the connecting wire, cable or optical fiber forms a ring. Data are passed along the ring from one computer to another, flowing in a single direction, and the network does not rely on a central host computer.

 

10.       Distinguish between a PBX and a LAN.

 

The PBX (private branch exchange) and the LAN (local area network) are similar in that they both serve a restricted setting of several hundred feet and both use the same kind of telecommunications media (twisted wire, coaxial cable or fiber optics). However, the PBX utilizes the firm's own telephone system, is based on the firm's internal telephone network and requires no special wiring. A LAN is more general purpose and is not tied to a telephone network, but requires special wiring, installed by the organization.

11.       Define a wide- area network (WAN).

 

A wide-area network (WAN) spans a broad geographical distance, ranging from several miles to the span of an entire continent. WANs are provided by common carriers, companies such as AT&T and MCI which are licensed by the government to provide communications services to the public. With a WAN the user is responsible for establishing the most efficient routing of messages, error checking, editing, devel­oping protocols and managing telecommunications.

12.       Define the following: modem, baud, Gateway, value-added network (VAN), packet switching, asynchronous transfer mode (ATM).

 

• A modem is a device to translate digital signals into analog signals and back again so that they can be transmitted through telecommunications media that handle only analog signals.
• Baud is a binary event, corresponding to a switch in voltage. At lower frequencies one baud generally sends one bit of information across a telecommunications medium but at higher frequencies, more than one bit is needed.
• A file server is a computer dedicated to storing data files or programs used by other computers in a network.
• Value-added network (VAN) is a private, multi-path, data-only, third-party managed telecommunications system that can provide economies in the cost of service and in network management because they are used by multiple organizations. The VAN "adds value" to communications by providing these addi­tional telecommunications management services.
• Packet switching maximizes utilization of telecommunications lines by dividing up lengthy blocks of data into bundles (of approximately 128 bytes each) called packets. Control information is attached to each packet rather than each bit, increasing speed and efficiency of transmission.
• ATM technology parcels information into uniform “cells,” eliminating the need for protocol conversion and so enabling the user to switch seamlessly between voice, data, images and video; it also ties LANs and WANs together more easily.

 

13.       Name and describe the telecommunications applications that can provide strategic benefits to businesses.

 

Telecommunications applications that can provide strategic benefits to businesses include:

• Electronic mail (e-mail): computer-to-computer exchange of messages.
• Voice mail: a system that digitizes spoken messages, transmits them over a network and stores the message for later retrieval. The system includes a range of capabilities including saving and routing to other parties.
• Facsimile (FAX): transmission of documents containing both text and graphics over ordinary telephone lines using a scanner to digitize the document.
• Teleconferencing: electronic meeting of people hundreds or even thousands of miles apart via telephone or electronic mail.
• Videoconferencing: teleconferencing that includes a video portion so that the individuals can actually see each other despite their distance.
• Electronic data interchange (EDI): direct computer-to-computer exchange between two organizations of standard business transaction documents such as invoices or purchase orders. Different from e-mail, EDI transmits actual, predefined structured transactions with distinct fields.

 

14.       What are the principal factors to consider when developing a telecommunications plan?

 

The major components of a telecommunications plan are:

• An assessment of the organization's existing telecommunications functions, their capabilities, limitations and exposures.
• Knowledge of the firm's strategic business plan and the contribution that can be made by telecommunications.
• Knowledge of how telecommunications supports the firm's daily operations, with identification of critical areas where telecommunications affects performance.
• Development of business (not technical) indicators showing how well the firm is fulfilling its plans for enhancing telecommunications.

 

The telecommunications plan will also need to address specific network requirements concerning:

• Distance for transmitting information.
• Security: the level of security required by the information to be transmitted via telecommunications.
• The range of telecommunications services to be supported, such as EDI, electronic mail, videoconferencing, etc.
• Access: whether multiple access by many users is required at many points throughout the organization or access is limited to a restricted group of users at one or two nodes.
• Utilization: assessment of the frequency and volume of communications.
• Costs of developing, operating, maintaining and expanding the telecommunications system and operating the network as well as overhead costs.
• Physical network installation problems.
• Connectivity: the problem faced in connecting multiple networks and in connecting hardware and software that meet so many different standards.