CoE 541 Exercise- DFD

INSTRUCTIONS: Read Lesson 5- Data Flow Diagram of our course handouts and answer the following questions.

1. What is DFD? What are the symbols used?
2. What are the different levels of DFD? How do they differ with each other? 
3. How do you create DFD?

CASE STUDY: On your selected small business organization. Develop DFD for your desired operation in their system. (E.g. small sari-sari store, a ticketing office, a drug store...). Show also DFD at different levels.

 Pass this exercise next meeting.

 

CoE 541 Re: Assignment - Lesson 4-

System Analysis and Design

4.19 A manager states the following as the goals of a production planning system:

            1 Reduce stock of semi-finished products.

            2 Provide better information for the production planning.

            3 Prevent overproduction.

           

            How would you quantify the goals? How would you obtain sub goals and

            quantify them if appropriate?

4.20 A university administrator calls a systems analyst to improve the administration

            of sponsored research projects. The main problems are delay in obtaining latest

            financial position to project coordinators, reconciliation of advances given to

            coordinators, prompt demands not sent to sponsors to collect promised grants and

            lack of information to answer following questions:

           

            Which areas of research get maximum grants?

            Which agency aids which type of projects?

            What trends can be seen in the nature of grants?

            Now:

            1. Classify the above problems into missing functions, unsatisfactory

            performance and excessive cost of operation.

            2. How would you get goals to meet the deficiencies?

            3. How would you quantify them?

4.21 A library receives 1300 journals of varying periodicities. The journals received

have to be recorded and displayed. Action has to be taken when journals are not

received in time or lost in mail. Unless request for replacement is sent quickly, it

may not be possible to get the replacement. Periodicals have to be ordered at

different times during the year and subscriptions renewed in time. Late payment

of subscription may lead to non-availability of earlier issues or paying higher

amounts for those issues. Current manual system is not able to meet these

requirements.

            1. Specify what should be the goals and sub-goals of an information system for

            ordering periodicals.

            2. Quantify these goals.

            3. Suggest alternative means of achieving the goals specified by you.

4.22 What operational, tactical, and strategic information should be provided by the

mess billing system mentioned in the text? (Case study).

4.23 When is a detailed system proposal prepared? What are the contents of a system

proposal?

V.

CoE 541 Module 3 - Information Gathering, Strategies and Methods

LEARNING UNIT 1

Information gathering, strategies, methods

INFORMATION GATHERING STRATEGIES
A strategy should be evolved by the analyst to gather information. The
strategy consists of identifying information sources, evolving a method of
obtaining information from the identified sources and using an information
flow model of organization

INFORMATION SOURCES
The main sources of information are users of the system, forms and
documents used in the organization, procedure manuals, rule books etc,
reports used by the organization and existing computer programs(If Any).

INFORMATION GATHERING METHODS
Searching for information
Information can be gathered by interviewing top-level management, middle
level management and operational staff. Besides Interviews group
discussions also help the analyst to gather information. It is not possible to
obtain all information in a single interview, more than one interview is thus
required.

PLANNING AN INTERVIEW
Before starting the interview the analyst must make a list of people to be
interviewed and in what order, plan and note down a list of questions to be
asked, plan several interviews with same person-mainly to clarify doubts
and interview groups as appropriate.

INTERVIEWING TECHNIQUE
There are some guidelines to ensure a successful interview:
Make an prior appointment with the person to be interviewed and meet him
at the allotted time. Read background material and go prepared with the
checklist. State purpose of interview. Be punctual and pay attention to what
user says. Do not use computer jargon. Obtain both quantitative and
qualitative Information. Discriminate between essential and desirable
requirements. State what you understand and get it confirmed. Do not
prolong interview and summarize the information gathered by you during
the interview and verify this with the user

USE OF QUESTIONNAIRES
Questionnaires are useful for collecting statistical data. Sometimes the
questionnaires are not promptly replied and several follow-ups/personal
interviews may be required to get questionnaires back from respondents
But if the questionnaires are short the probability of getting the reply is high
When data has to be collected form large number of people questionnaires
are useful.

OTHER METHODS OF INFORMATION GATHERING
Other methods of information search are:
􀂃 Systems used in other similar organization
􀂃 Observe workflow in workplace
􀂃 Repository of systems developed for similar organizations available.

LEARNING UNIT 2

System requirements specification, classification of
requirements as strategic, tactical, operational and statutory

SYSTEM REQUIREMENTS SPECIFICATION (SRS)
SRS is obtained after excessive discussions with the user.
System requirements specification specifies what Information requirements
will be provided. It does not specify how the system will be designed.
Developing SRS is most important and difficult task of a Systems analyst
How SRS is developed
Analyst examines the current system, finds out the shortcomings of the
system as seen by the user. He then develops an SRS which is
understandable by the user and which can be used for detailed design of the
system.

Ideal characteristics of SRS
􀂃Complete and Unambiguous.
􀂃Specifies operational, tactical, and strategic information requirements
􀂃Eliminates possible later disputes between users and Analyst
􀂃Uses Graphical aids understood by users who are not computer literate and
will also be useful in design.
􀂃Jargon Free.

DEVELOPING A DOCUMENT FLOW DIAGRAM
EXAMPLE WORD STATEMENT
“Our company receives many items from several vendors each accompanied
by a delivery note. A receiving office receives the item and checks the
delivery note with corresponding order. Any discrepancy is reported to
purchase office. The items received along with items received note (with
details of items) is sent to the inspection office.”

ENTITIES IDENTIFIED-Vendors, Receiving office, Inspection office
DOCUMENTS IDENTIFIED-Delivery note, discrepancy note, Items
Received note.
Using these a document flow diagram is drawn
The diagram is interpreted as follows:
1) Vendors deliver items to receiving office accompanied by a delivery note
2) Receiving Office sends items to inspection office along with an items
received note
3) Receiving office sends discrepancy note to Purchase office

ENTITIES: Vendor, Receiving office, Inspection office and purchase
office

DOCUMENTS: Delivery note, Items received note and discrepancy note
Vendor Receiving
Office
Inspection
office
Purchase
Office
Delivery note Items
Received
Discrepancy note
note
Delayed Items Delivered Items
Indicates Physical
flow of items
Indicates Documents

DATA FLOW DIAGRAM (DFD)
DFD has entities and data flows, DFD specifies processing performed by
some of the entities. It specifies which entities generate documents and also
indicate their flow. Data stores which are referred while processing data and
in which processed data may be written or stored are also represented in the
Diagram
•Entities are, originators of data and “consumers” of data
•Vendor, Inspection office and purchase office are entities in the above
diagram
•Data flows are delivery note, items received note and discrepancy note
•A circle is used to depict a process
•A pair of parallel lines depict a store
Vendor
Receiving
Process
Inspection
Office
Purchase
Office
Orders
Delivery
note
Items
Received
note
Discrepancy
note
Data elements in the data flow:
Delivery note:
Order no,Vendor code,Vendor name and address,Item name, Item
code,Delivery date,Quantity supplied,units.
Items Received note:
Order no,Item name,Item code,Delivery date,quantity,supplied,units.
Discrepancy note:
Order no,Vendor code,Vendor name and address,Item name, Item
code,Order date, Delivery date,quantity supplied,units, excess/deficiency,No
of days late/early.
Receiving office order file
Order no,Order date,Item name,Item code,Vendor code,Vendor Name and
address,Quantity ordered,delivery period.
PROCESSING RULE
The statements given below are shown to the user for his approval.
English statement
1.Compare order no in delivery note with that in order file. If no match
return item to vendor.
2.If order no matches then compare item codes, if no match return item to
the vendor.
3. If order number matches compare qty delivered with quantity ordered. If
excess or deficient send discrepancy note to purchase office.
4. If order number matches compare date of delivery with expected date. If
late or early send discrepancy note to purchase office.
5.In case3 and case4 send items received note to inspection office

MODULARIZING REQUIREMENTS SPECIFICATIONS
SRS Document now consists of Document flow diagrams(as many as
needed), Data Flow Diagrams, Data elements of each data flow and Data
store, processing rules carried out in each circle of DFD, a descriptive
statement of operational,tactical,strategic information will be provided,
a data dictionary which consolidates all data elements in the document and
data store.

CoE 541 Module 2 - System Analysis and Design Life Cycle

LEARNING UNIT 1

Systems Analysis and Design life Cycle: Requirements
determination, requirements specifications

LIFE CYCLE OF SYSTEMS ANALYSIS AND DESIGN
Steps involved in Analysis and Design
1.Requirements Determinations
2.Requirements Specifications
3.Feasibility Analysis
4.Final Specifications
5.Hardware Study
6.System Design
7.System Implementation
8.System Evaluation
9.System Modification

1.Requirements Determination:
This is arrived at by a consensus reached among managers in the
organization. Priorities among applications are determined and high priority
applications are selected.

2.Requirements Specifications
This is known as System Requirements Specification (SRS). Applications
where a system is required are listed, and specifications of the users
requirements are arrived at after discussion with the user.

LEARNING UNIT 2

Feasibility analysis, final specifications, hardware and
software study, system design, system implementation,
system evaluation, system modification.
3. Feasibility Analysis
Formulate Goals of the system and quantify them. Find alternative methods
of meeting the goals and for each alternative assess resources needed like
Human Resources, Time and Money, Equipment needed etc. Assess cost of
each alternative and find the best alternative
4.Final Specifications
Specifications would state what the system would achieve. Specifications
drawn up are then improved for implementation. SRS is written, which is
then given to user and agreement is reached
5.Hardware Study
Determine Hardware and Software required to execute the application.
Determine Response time, Volume of data to be processed, Frequency of
reports etc & then pick the hardware.
6.System Design
A logical Design of the System is implemented. Objects are identified,
Database is designed, and program specification and implementation plan is
drawn up.
7.System Implementation
In this phase programs are written, Database is created, user operational
document is created, users are trained and the system is tested with
operational data
8.System Evaluation
Find out from Users whether the System meets the specified requirements.
List areas of dissatisfaction and find reasons, suggest if there has to be any
improvements to the system
9.System Modification
Fix the errors, add/delete features as required by users, tune the system and
continuously monitor system and assess performance.

LEARNING UNIT 3

Role of systems analyst, attributes of system analyst, tools

used in system analysis

ROLE OF SYSTEMS ANALYST
The following are roles of systems analyst:
1. Defining Requirements: Involves Interviewing Users
2. Prioritizing Requirements: Obtain Users Consensus
3. Fact Gathering: Data, Facts and opinions of Managers are gathered,
Lower level Users should also be consulted
4.Analysis and evaluation -Arrive at appropriate system
5. Solving problems: Hazy requirements converted into specific
requirements, suggest many alternative solutions, and quantify cost and
benefits
6.Drawing up specifications: Draw up specifications which are understood
by users and programmers, which are accepted by users and which are
precise and detailed.
7. System design: Logical design of system is implemented and the design
must be modular
8.Evaluating Systems: Evaluate the system after it has been used for
sometime, Plan the periodicity for evaluation and modify the system as
needed

ATTRIBUTES OF A SYSTEMS ANALYST
Knowledge of organisation
Knowledge of computers and software
Good interpersonal relations
Ability to communicate
Analytical mind
Breadth of knowledge

TOOLS USED BY SYSTEMS ANALYST
􀂃 Data Flow Diagram
􀂃 Decision Tables
􀂃 Modeling Language such as UML
􀂃 Normalization of Databases
􀂃 Testing tools
􀂃 ISO/CMM procedure manuals

CoE 541 E-book

Click here to download the e-book below.

CoE 541 Module 1 - Data and Information

MODULE 1

Learning Unit 1

Data and Information, types of information : Operational,
tactical, strategic, Statutory

DATA AND INFORMATION
DATA is a raw material with which we begin. Collecting data costs money
and hence one must collect necessary and sufficient data. Data is generally
used by machines and is useless unless it is processed to create
INFORMATION.
INFORMATION is Processed data, used by managers to initiate actions and
to run the organization efficiently. The data processed by machines gives
information

TYPES OF INFORMATION
􀂃STRATEGIC : Needed for long range planning and directions. This is less
structured.
􀂃 TACTICAL : Needed to take short range decisions to improve profitability
and performance.
􀂃OPERATIONAL : Needed for day to day operations of the organization.
Eg: Daily Sales, Billing.
􀂃STATUTORY : Needed by law to sent to government authorities.
Eg: Sales tax return.

MANAGEMENT HIERARCHY AND INFORMATION NEEDS
Top
Managers
Middle
Managers
Line managers
Volume of
Information
Type of
Information
Low
condensed
Medium
moderately
processed
Large
Detailed Reports
Unstructured
Moderately
structured
Highly
structured
Tactical
Short range improvement
Strategic-
Long range planning
Operational
Day to day policies

Learning Unit 2

Why do we need information systems, management structure,
requirements of information at different levels of management

NEED FOR INFORMATION SYSTEMS
Information systems are needed when timely processing for fast action is
needed, same data has to be processed in different ways and when
organizations require innovative processing.

MANAGEMENT STRUCTURE
Chief Executive (Strategical)
Functional areas of management are as follows:
Production
manager
Marketing
manager
Materials
manager
Finance
manager
Human
Resource
manager
Line managers
􀂃PRODUCTION
􀂃 MARKETING
􀂃 MATERIALS – purchase, stores
􀂃 FINANCE –Accounts
􀂃 HUMAN RESOURCE DEVELOPMENT(HRD)
􀂃 RESEARCH AND DEVELOPMENT (R&D)

INFORMATION FOR MANAGEMENT
A Production Management
The following type of information is needed in production management:
Strategic Information:
1)Yearly and monthly production quotas and alternate schedules
2)Policies on machine replacement, augmentation and modernization.
3)Identifying best product mix.
Tactical Information
1)Identifying and controlling areas of high cost.
2) Identifying critical bottlenecks in production.
3) Identifying alternate production schedules based on tools, machines etc.
4) Performance measures of machines to decide replacement.
Operational Information
1)Monitoring up to date production information by examining assemblies,
detecting likely shortages and giving early warning.
2) Scheduling better production dynamically.
3) Preventive maintenance schedules.
4) Monitoring tool, machine and personnel availability
B Marketing Management
Strategic Information:
1) Search for new markets and marketing strategies.
2) Analysis of competitors strategy
3) Technology and demographic forecasts and product changes
Tactical Information:
1)Advertising techniques and analysis of their impact.
2)Customer preference surveys.
3)Correlation of prices and sales.
4)Sales force deployment and targets.
5)Exploring alternate marketing channels.
6)Timing of special sales campaigns.
Operational Information:
1) Sales analysis by regions, customer class, sales person.
2) Sales target versus achievement.
3) Market share and trends.
4) Seasonal variations.
5) Effect of model changes.
6) Performance of sales outlets
7) Costs of campaigns and benefit.
C Material Management
Strategic Information:
1) Developing vendors for critical items
2) Determining optimal levels of inventory
3) Determining proportion of material needed
4) Reducing varieties of inventory
Tactical Information:
1) Developing vendor performance measures.
2) Determining optimal reorder levels.
3) Determining issues of items to shops versus
4) standard needs.
5) Controlling high value of inventory.
6) Determining impact on material cost and
7) procurement with design changes and new
8) product introduction.
Operational Information:
1) List of excess & deficient items received.
2) List of items rejected.
3) Critical items received.
4) Stores in transit and in inspection.
5) Value of inventory in hand.
6) Goods received, rejected and issued.
D Finance Management
Strategic Information:
1) Methods of financing.
2) Pricing policies
3) Tax planning.
Tactical Information:
1) Variations between budget and expenses.
2) Large outstanding payments/Receipts.
3) Credit and payment status.
4) Cost increases and pricing.
5) Impact of taxation on pricing
Operational Information:
1) Periodic financial report.
2) Budget status to all functional managers.
3) Tax returns.
4) Share transfers.
5) Profit and loss account.
6) Payments and receipts.
7) Payroll,provident fund accounts.
E Human Resource Management
Strategic Information:
1) Long range human resource requirements at different levels.
2) Policies on human resource development and training
3) Policies on personnel welfare and facilities
Tactical Information:
1) Performance appraisal.
2) Demographic make-up of personnel and its impact on retirement.
3) Production incentives.
4) Morale of personnel.
5) Absentee reduction.
6) Leave and overtime policies.
7) Personnel deployment policies.
Operational Information:
1) Routine assessment.
2) Skills inventory.
3) Loan/advances and recoveries.
4) Leave record.

CoE 541 Course Syllabus

SYSTEM ANALYSIS AND DESIGN

Course Syllabus

Module 1: Data and Information (3)
Types of information: operational, tactical, strategic and statutory – why do we need
information systems – management structure – requirements of information at different
levels of management – functional allocation of management – requirements of
information for various functions – qualities of information – small case study.

Module 2: Systems Analysis and Design Life Cycle (3)
Requirements determination – requirements specifications – feasibility analysis – final
specifications – hardware and software study – system design – system implementation –
system evaluation – system modification. Role of systems analyst – attributes of a
systems analyst – tools used in system analysis

Module 3: Information gathering (3)
Strategies – methods – case study – documenting study – system requirements
specification – from narratives of requirements to classification of requirements as
strategic, tactical, operational and statutory. Example case study
Module 4: Feasibility analysis (3)
Deciding project goals – examining alternative solutions – cost – benefit analysis –
quantifications of costs and benefits – payback period – system proposal preparation for
managements – parts and documentation of a proposal – tools for prototype creation

Module 5: Tools for systems analysts (3)
Data flow diagrams – case study for use of DFD, good conventions – leveling of DFDs –
leveling rules – logical and physical DFDs – software tools to create DFDs
Module 6: Structured systems analysis and design (3)
Procedure specifications in structured English – examples and cases – decision tables for
complex logical specifications – specification oriented design vs procedure oriented
design

Module 7: Data oriented systems design (3)
Entity relationship model – E-R diagrams – relationships cardinality and participation –
normalizing relations – various normal forms and their need – some examples of
relational data base design.

Module 8: Data input methods (3)
Coding techniques – requirements of coding schemes – error detection of codes –
validating input data – input data controls interactive data input
Module 9: Designing outputs (2)
Output devices – designing output reports – screen design – graphical user interfaces –
interactive I/O on terminals.

Module 10: Object oriented systems modeling (4)
What are objects? – Why objects? – Objects and their properties – classes – inheritance –
polymorphism – how to identify objects in an application – how to model systems using
objects – some cases of object oriented system modeling

Module 11: Control – audit and security of information systems (4)
Audit and security of information systems – why controls are needed – objectives of
control – techniques used in control – auditing information systems – auditing around,
through and with the computer – testing information systems – types of tests – how to
generate tests – security of information systems – disaster recovery – business process
continuity

Module 12: Systems analysis and design in the era of electronic commerce (3)
B2B, B2C and C2C e-commerce – advantages and disadvantages of e-commerce. Ecommerce
system architecture – physical networks, logical network, World Wide Web,
web-services – html, XML.

Module 13: Electronic data interchange (2)
EDI standards – virtual private networks – XML and EDI.

Module 14: Security of e-commerce transactions, firewalls (3)
Encryption methods – symmetric and asymmetric encryption – digital signature –
certifying authorities for signatures – legal status of e-commerce transactions

Module 15: Payment systems in e-commerce (2)
Cheque payment, credit card payments, e-cash payments.

Module 16: Complete system analysis and design case studies (5)
A system for journal acquisition in libraries – walk through the entire life cycle