Systems Analysis Midterm 2

Conceptual data modeling is typically done in parallel with other requirements analysis and structuring steps during ______

systems analysis

A renewal is an example of a(n):

entity

Data contained on a customer order form would be represented on a data-flow diagram as a:

data flow A data flow is data that are in motion and moving as a unit from one place in a system to another. A data flow could represent data on a customer order form or a payroll check.

On a data-flow diagram, a rectangle with the right vertical line missing represents a:

data store A data store represents data at rest, which may take the form of many different physical representations

On an entity-relationship diagram, the entity's identifier is:

underlined on an E-R diagram

Briefly identify and describe the participants of a JAD session.

A JAD session consists of a JAD session leader, users, managers, a sponsor, systems analysts, a scribe, and information systems staff. The JAD session leader is responsible for running the session. The scribe is the individual who takes notes during the session. Users are important because they understand the current system. Managers are needed to provide insight into new organizational directions, motivations, organizational impacts of systems, and support for requirements determined during the JAD. Since new systems cost money, high-level management support is demonstrated through the appearance of a system sponsor. Attendance by this individual is usually at the beginning or ending of the session. Systems analysts are present so they can learn from the users and managers. Information systems staff can contribute ideas to the process as well as learn from it.

Which of the following is most likely a source/sink for a manufacturing system?

A bank A bank is a component outside the system and would likely be considered a sink in a data flow diagram.

Which of the following is NOT a true statement regarding data flows?

A data flow can go directly back to the same process it leaves. Although data may flow in both directions, it is usually indicated by two separate arrows and doesn't flow directly back to the same process it leaves.

Double-ended arrows are used to represent data flowing in both directions.

Although data may flow in both directions, it is usually indicated by two separate arrows.

Which of the following is NOT a process modeling deliverable?

An entity relationship diagram In structured analysis, the primary deliverables from process modeling are a set of coherent, interrelated data-flow diagrams.

You should use the interview process to set expectations about the new or replacement system.

Be careful during the interview not to set expectations about the new or replacement system unless you are sure these features will be part of the delivered system.

Contrast data modeling to process modeling and logic modeling.

Data modeling focuses on the data that must be stored by the system. Data-flow diagrams and the processing logic techniques demonstrate how, where, and when data are used or modified by the system. However, these techniques do not illustrate the definition, structure, and relationships within the data. Data modeling complements the process modeling and logic modeling techniques.

What is decomposition? What is balancing? How can you determine if DFDs are not balanced?

Decomposition is the iterative process by which a system description is broken down into finer and finer detail, creating a set of diagrams in which one process on a given diagram is explained in greater detail on a lower-level diagram. Balancing is the conservation of inputs and outputs to a data-flow diagram process when that process is decomposed to a lower level. You can determine if a set of DFDs are balanced or not by observing whether or not a process that appears in a level-n diagram has the same inputs and outputs when decomposed for a lower-level diagram.

Analysts should use intelligent keys as identifiers.

False Avoid the use of so-called intelligent keys, whose structure indicates classifications, locations, and other entity properties.

When constructing data-flow diagrams, you should show the interactions that occur between sources and sinks.

False Because sources and sinks are outside the system we are studying, many of their characteristics and interactions are of no interest to us.

One of the primary purposes of a DFD is to represent time, giving a good indication of whether data flows occur constantly in real time, once a day, or once a year.

False DFDs do not do a good job of representing time. A given DFD provides no indication of whether a data flow occurs constantly in real time, once per week, or once per year.

Processes, rather than data, are the most complex aspects of many modern information systems.

False For example, transaction processing systems can have considerable complexity in validating data, reconciling errors, and coordinating the movement of data to various databases.

On a data-flow diagram, an arrow represents an action, such as calculating an employee's pay.

False On a data-flow diagram, an arrow represents a data flow, not an action. An action is considered a process.

The calculation of a student's grade is represented on a data-flow diagram as a data flow.

False The calculation of a student's grade would be represented as a process, where data is transformed.

Assume shipment data are entered into a logbook once shipments are received at the company's warehouse; the logbook is represented on a data-flow diagram as a sink.

False The logbook would be represented as a data store as it is data at rest and it is still within the system concerned.

Open-ended questions put the interviewee at ease, are easily summarized, and save time.

False While open-ended question tend to put the interviewee at ease, this data is not easily summarized and take additional time to interpret.

Ideally, each data store on a primitive data-flow diagram will be an individual attribute.

False Each data store on a primitive data-flow diagram will be an individual entity.

Logic modeling graphically represents the processes that capture, manipulate, store, and distribute data between a system and its environment and among components within a system.

False Process modeling, not logic modeling, involves graphically representing the processes, or actions, that capture, manipulate, store, and distribute data between a system.

A primitive level data-flow diagram is the first deliverable produced during requirements structuring.

False The first deliverable produced during requirements structuring is the context data-flow diagram, which shows the scope of the system, indicating which elements are inside and outside the system.

The goal with using prototyping to support requirements determination is to build the ultimate system from prototyping.

False The goal with using prototyping to support requirements determination is to develop concrete specifications for the ultimate system, not to build the ultimate system.

The lowest-level data-flow diagrams are called level-0 diagrams.

False The lowest-level data-flow diagrams are called primitive DFDs.

Social security number, last name, and first name are examples of entity types.

False These are all examples of Attributes. An entity type for these attributes might be STUDENT.

A JAD is an inexpensive, popular requirements determination technique.

False A JAD employs thousands of dollars of corporate resources, the most expensive of which is the time of the people involved.

The decomposition of Process 2.4.3.4 would be shown on a level-4 diagram

False The decomposition of Process 2.4.3.4 would be shown on a level-3 diagram.

Which of the following is a true statement regarding midrange alternatives?

Midrange alternative design strategies represent compromise solutions. Midrange represents a middle point between the low which represents the least number of design components necessary to solve the problem and high which goes beyond just solving the problem.

Which of the following is a reason for directly observing end users?

People often do not have a completely accurate appreciation of what they do or how they do it.

Which of the following is a true statement regarding sources/sinks?

Sources/sinks are always outside the information system Being outside of the system also helps define the boundaries of the system.

Explain in detail what alternative design strategies system analysts generate for manager's decision

The generation of at least three alternative solutions was recommended. The three alternatives represent both ends and the middle of the alternative solution spectrum. A low-end solution, high-end solution, and midrange solution should be identified. Low-end solutions are conservative in terms of the effort, cost, and technology involved in developing a new system. This strategy provides all the required functionality users demand with a system and will meet every constraint. High-end solutions are potential solutions that contain many extra features users may desire. High-end solutions focus on functionality, not cost. High-end solutions will ignore most-if not all-system constraints. Midrange solutions are compromise solutions.

Compare collecting information through observation and through document analysis. Describe a hypothetical situation in which each of these methods would be an effective way to collect information system requirements.

The observation method is high in information richness; requires significant time, can be expensive, and provides the chance for follow-up and probing. The observee is known to the analyst and the potential audience is small. For example, when being asked how much he is usually interrupted by calls and visits resulting in being away from his daily work, an employee's recalling is not always reliable, even when they try to be and say what they think is the truth. Because people cannot always be trusted to interpret and report their own actions reliably, you can supplement what people tell you by watching what they do in work situations. In contrast, the information richness of document analysis is low and old; the time required is low to moderate; its expense is low to moderate, and the chance for follow-up is limited. The confidentiality of the document depends on the nature of the document; there is no clear commitment on the subject's part, and there is potentially bias by which documents were retained. (You may develop a case illustrating the necessity of using document analysis.)

Which of the following is a true statement regarding JAD?

The primary purpose of using JAD in the analysis phase is to collect systems requirements simultaneously from the key people involved with the system.

What are the steps in creating a decision table? How do you reduce the size and complexity of a decision table?

The steps for creating a decision table are: 1. name the conditions and the values each condition can assume; 2. name all possible actions that can occur; 3. list all possible rules; 4. define the actions for each rule; and 5. simplify the decision table. To reduce the size and complexity of a decision table, use separate, linked decision tables, or use numbers that indicate sequence rather than Xs where rules and action stubs intersect. Also, the analyst should identify indifferent conditions and simplify the decision table.

A first step in any BPR effort is to understand what processes need to change.

True A first step in any BPR effort is to understand what processes need to change, what the key business processes are for the organization.

One way to handle repeating data within an entity is to separate the repeating data into another entity, called a weak entity.

True A weak entity is an entity that would not exist if not for the related parent entity.

Analysts should consider substituting single-attribute surrogate keys for large composite keys.

True An employee's skills are considered multivalued because the employee likely has a number of skills (i.e., hard worker, SQL expert...).

When referencing an employee entity, an employee's skills are an example of a multivalued attribute.

True An employee's skills are considered multivalued because the employee likely has a number of skills (i.e., hard worker, SQL expert...).

Relationships are labeled with verb phrases.

True For example, an EMPLOYEE has a LOCKER. A verb is used to describe the relationship.

The minimum cardinality of a relationship is the minimum number of instances of entity B that may be associated with each instance of entity A.

True Minimum usually includes 0 or 1 using crow's feet notation.

A context diagram shows the scope of the organizational system, system boundaries, external entities that interact with the system, and the major information flows between entities and the system.

True The boundary or scope of this system, and the system's relationship to its environment, is represented by a data-flow diagram called a context diagram.

The primary deliverable for the conceptual data-modeling step within the analysis phase is an entity-relationship diagram.

True The entity-relationship diagram is delivered along with a project dictionary that contains additional information about the model.

The purpose of the conceptual data model is to show as many rules about the meaning and interrelationships among data as possible.

True The model serves as a blue print for a later stage of data design and implementation. Rules that don't show up on the data model should be placed in the project dictionary.

The names of data stores on primitive-level data flow diagrams often correspond to the names of data entities in entity-relationship (E-R) diagrams.

True The names of data stores on primitive-level DFDs often correspond to the names of data entities in entity-relationship diagrams, and the data elements in data flows on DFDs must be attributes of entities and relationships in entity-relationship diagrams.

The idea behind BPR is to reorganize the complete flow of data in major sections of an organization to eliminate unnecessary steps, achieve synergies among previously separate steps, and become more responsive to future changes.

True The overall process by which current methods are replaced with radically new methods is referred to as business process reengineering (BPR).

Meeting notes, procedure manuals, and consultant reports are specific deliverables that might be obtained during the requirements determination process.

True The primary deliverables from requirements determination are the types of information gathered during the determination process. The information can take many forms: transcripts of interviews; notes from observation and analysis of documents; sets of forms, reports, job descriptions, and other documents; and computer-generated output such as system prototypes.

Joint application design and prototyping can help keep the analysis effort at a minimum yet still effective.

True The primary purpose of using JAD in the analysis phase is to collect systems requirements simultaneously from the key people involved with the system.

Functional decomposition is a repetitive process of breaking the description or perspective of a system down into finer and finer detail.

True This process creates a set of hierarchically related charts in which one process on a given chart is explained in greater detail on another chart.

In documents you can find information about the values of the organization or individuals who can help determine priorities for different capabilities desired by different users.

True Values of the organization or individuals who can help determine priorities for different capabilities desired by different users (e.g., maintaining market share even if it means lower short-term profits).

The characteristics of data captured during data modeling are crucial in the design of databases, programs, computer screens, and printed reports.

True Without quality data modeling, programs and reports may not provide critical information.

Collection of information is at the core of systems analysis.

True You must collect information about the information systems that are currently in use. You need to find out how users would like to improve the current systems and organizational operations with new or replacement information systems. This is core to systems analysis.

Data-flow diagramming is one of several structured analysis techniques used to increase software development productivity.

True Some organizations, such as EDS, have developed their own type of diagrams to model processes.

The primary deliverables from requirements determination include:

a completed prototype The primary deliverables from requirements determination are the types of information gathered during the determination process, which may include (1) information collected from conversations with users, such as interview transcripts, notes from observations, meeting notes; (2) existing documents and files, such as business mission and strategy statement, sample business forms and reports, computer displays, procedure manuals, job descriptions, reports, etc.; and (3) computer-based information, such as results from JAD sessions, CASE repository contents and reports of existing systems, displays and reports from system prototypes.

An attribute that can have more than one value for each entity instance is referred to as:

a multivalued attribute Consider an EMPLOYEE and his or her dependents. Dependent name, age, and relation to employee (spouse, child, parent, etc.) are multivalued attributes about an employee, and these attributes repeat together.

If two processes are connected by a data flow, they are said to:

be coupled to each other In this case, we would say the processes are coupled to each other. For instance, if Process 7.4 produces a data flow and that Process 7.2 must be ready to accept it; we would say that these processes are physically linked to each other, or "coupled".

If your analysis of several written procedures reveals a duplication of effort in two jobs, you should:

call the duplication to the attention of management as an issue to be resolved before system design can proceed In some cases such as duplication, it may be necessary to redesign the organization before the redesign of an information system can achieve its full benefits.

Questions in interviews and on questionnaires asking those responding to choose from a set of specified responses are:

close-ended questions

Prototyping is most useful for requirements determination when:

communication problems have existed in the past between users and analysts Often, both parties want to be sure that system requirements are as specific as possible to avoid communication problems.

A particular approach to developing an information system best describes:

design strategy A design strategy includes statements on the system's functionality, hardware and system software platform, and method for acquisition.

The purpose of requirements structuring is to:

enable the large amount of information gathered during requirements determination to be organized The amount of information gathered during requirements determination is often very large, especially if the scope of the system under development is broad. Requirements structuring provides a basis for organization of the information.

On an entity-relationship diagram, a rectangle represents a(n):

entity

A single occurrence of an entity type defines:

entity instance For instance, your specific information (LastName, FirstName) would be an example of an entity instance.

A candidate key that has been selected as the unique, identifying characteristic for an entity type is called a(n):

identifier You can have many candidate keys that uniquely identify an entity instance, but only one is chosen as an identifier.

The structured, measured set of activities designed to produce a specific output for a particular customer or market best defines:

key business processess In other words, key business processes would include all activities used to design, build, deliver, support, and service a particular product for a particular customer.

A data-flow diagram that represents a system's major processes, data flows, and data stores at a high level of detail refers to a:

level-0 diagram The single process, labeled "0," represents the entire system; all context diagrams have only one process labeled "0."

Which of the following types of alternatives represent compromise solutions?

midrange alternatives Midrange represents a middle point between the low which represents the least number of design components necessary to solve the problem and high which goes beyond just solving the problem.

Data-flow diagrams allow you to:

model how data flow through an information system. A data-flow diagram is a graphic that illustrates the movement of data between external entities and the processes and data stores within a system.

One advantage of open-ended questions in an interview is:

previously unknown information can result Open-ended questions are usually used to probe for information when you cannot anticipate all possible responses. Finding unexpected or previously unknown information is a potential benefit of using open-ended question.

Since data-flow diagrams concentrate on the movement of data between processes, these diagrams are often referred to as:

process models Specifically, process modeling involves graphically representing the processes, or actions, that capture, manipulate, store, and distribute data between a system and its environment and among components within a system.

An association between the instances of one or more entity types that is of interest to the organization best defines:

relationship The relationship is represented by lines and verbs are used to describe the relationships.

Analysts gathering information from as many sources as possible about what the new system should do is indicative of:

requirements determination During requirements determination, you and other analysts gather information on what the system should do from as many sources as possible. Such sources include users of the current system, reports, forms, and procedures.

Good interview guidelines consist of:

seeking a variety of perspectives from the interviews Seeking a variety of perspectives from the interviews allows the investigator to triangulate the information and will likely avoid costly mistakes.

If entity B is a mandatory participant, then:

the minimum cardinality of the relationship is one In Crow's feet notion, this one represented as a "|" representing one mandatory.

The analysis of documents can help you identify:

the reason why current systems are designed the way they are Sometimes better understanding why current systems are designed the way they are can provide useful information when determining system improvements.

The data modeling perspective that derives the business rules for a data model from an intimate understanding of the nature of the business, rather than from any specific information requirements in screens, reports, or business forms, is referred to as the ______

top-down approach

A relationship between the instances of one entity type is a:

unary relationship An example of a unary relationship is a customer being referred by another customer. Both customers are from the same entity.