Systems Analysis Methods Part 2

 Systems Analysis Methods Part 2

Project Management is the process of planning and controlling development of a system within a specified timeframe at a minimum cost with the right functionality. This applies to any system.

A project manager has the primary responsibility for managing the hundreds of tasks and roles that need to be carefully coordinated.

In the 2000 Standish Group Study

Only 28% of system development projects successful.

72% of projects cancelled, completed late, completed over budget, and/or limited in functionality.

Key Steps in Managing a project

·         Identifying project size (scope)

·         Creating and managing the work-plan

·         Staffing the project

·         Coordinating project activities

Types of Project Management Software: Microsoft Project, Plan View, PM Office

Identifying project size

Project Manager’s Balancing Act

·         Project Management involves making trade-offs

·         Modifying one element requires adjusting the others

Project Estimation (Guess –ta- mate)

·         The process of assigning projected values for time and effort

·         Sources of estimates

¨       Methodology in use

¨       Actual previous projects

¨       Experienced developers

·          Estimates begin as a range and become more specific as the project progresses

	Planning	Analysis	Design	Implementation
Typical industry standards for business applications	15%	20%	35%	30%
Estimates based on actual figures for first stages of SDLC	Actual	Estimated	Estimated	Estimated
	4 person	5.33 person	9.33 person	8 person
	months	months	months	months

SDLC= system development life cycle

Creating and Managing the work plan

Work Plan Information	Example
Name of  task Start date Completion date Person assigned Deliverable (s) Completion status Priority Resources needed Estimated time Actual time	Preform economic feasibility Jan 05,2005 Jan 19, 2005 Project sponsor: Mary Smith Cost-benefit analysis Open High Spreadsheet 16 hours 14.5 hours

LOC = Line of Code

Project Work plan

·         List of all tasks in the work breakdown structure, plus

·         Duration of task

·         Current task status

·         Task dependencies

·         Milestone (dates)

Tracking Project Tasks

·         Gantt Chart

·         Bar chart format

·         Useful to monitor project status at any point in time

Pert Chart

·         Flowchart format

·         Illustrate task dependencies

Identifying Tasks

·         Methodology

§  Using standard list of tasks

·         Top-down approach

·         Identify highest level tasks

·         Break them into increasingly smaller units

·         Organize into work breakdown structure

Managing Scope

·         Scope creep (size)

·         JAD and prototyping(joint application development)

·         Formal change approval

·         Defer additional requirements as future system enhancements

Time boxing

·         Fixed deadline

·         Reduced functionality, if necessary

·         Fewer “finishing touches”

Staffing the Project

Staffing Attributes

·         Staffing levels will change over a project’s lifetime

·         Adding staff may add more overhead than additional labour ”Brooke” said that

·         Using teams of 8-10 reporting in a hierarchical structure can reduce complexity

Coordinating Project Activities

Case Tools

Planning              Analysis               Design                  Implementation

                Upper CASE                                        Lower CASE

                                                Integrated CASE (I-CASE)

Classic Mistakes

·         Overly optimistic schedule

·         Failing to monitor schedule

·         Failing to update schedule

·         Adding people to a late project

Oversight committee

Project manager works with Client, Users, Subcontractors, Team leaders, They are all members

Feasibility

Feasibility is a measure of how beneficial or practical the development of an information system will be to an organization

Feasibility analysis/study is the process by which feasibility is measured. A project that is feasible at one point in time may become infeasible at a later point

Concept of feasibility checkpoints

Four Tests for Feasibility

1.       Operational

2.       Technical

3.       Schedule

4.       Legal

5.       Economic

·         Operational feasibility

Operational feasibility measures how well the solution of problems or specific solution will work in the organization

·         Feasibility tests

It is also a measure of how people feel about the system/project

How do the end-users and management feel about the problem solution

·         Technical feasibility

Measures the practicality of a specific technical solution and the availability of technical resources and expertise

Most difficult area to asses at this stage

Go/ No Go Design

Feasibility tests

Three major considerations

Development Risk: can the system element be designed so that necessary function and performance are achieved within the constraints uncovered during analysis

Resource availability:

Has relevant technology progressed to a state to support the system?

Schedule feasibility:

Measures how reasonable the project timeline is given our technical expertise, are the project deadlines reasonable?

Missed schedule are bad but inadequate systems are worse

Feasibility Tests need to determine whether the deadlines are mandatory or desirable. It is preferable (unless the deadline is absolutely mandatory) to deliver a properly functioning information system late than to deliver an error-prone information system on time.

Legal Feasibility

Legal Feasibility is a determination of any infringement, violation or liability that could result from development of a system.

All projects are feasible – given unlimited resources and infinite time!

Economic Feasibility

Measures the cost effectiveness of a project or solution. Often called a cost-benefit analysis.

Generally the bottom line consideration for most systems. Exceptions: national defence systems, high technology applications e.g. Space Program.

System Development Costs

Usually once off costs that will not recur after the project has been completed.

·         Facilities

·         Equipment and installation

·         Software and licences

·         Consulting fees

·         Training/ personnel costs

The lifetime benefits must recover both the developmental and operating costs. (Key)

System Operating Costs

System Operating Costs Recur throughout the lifetime of the system.

Costs classified as fixed and variable

Fixed costs  occur at regular intervals and at relatively fixed rates

·         Lease

·         Salaries

Variable costs occur in proportion to some usage factor

·         Supplies

·         Overhead costs         e.g. utilities, maintenance

What Benefits Will The System Provide?

Benefits normally increase profits or decrease costs.

Tangible Benefits

Tangible Benefits are those that can be easily quantified.

Measured in terms of monthly or annual savings or profit to the firm.

·         Fewer processing errors

·         Reduced expenses

·         Increased sales

·         Reducing staff- automation of manual functions

Intangible benefits

Intangible benefits are those benefits believed to be difficult or impossible to quantify

Improved customer goodwill

Improved employee moral

Sales tracking system which leads to better information for marking decisions

·         Reputation

Pay Back Analysis

Break-even point is when lifetime benefits will overtake the lifetime costs.

A.      Will our current printer be able to handle the new reports and forms required of a new system?    Technical.

B.      What are the fixed and variable costs of the operating the system?    Economic

C.      Does the system provide adequate throughput and response time?  Operational

D.      Does the system offer adequate service level and capacity to reduce the costs of business or increase the profits of the business?  Operational

E.       What are the tangible and intangible benefits of the system?  Economic

F.       Does the system offer adequate controls to ensure against fraud and embezzlement and to guarantee the accuracy and security of data and information?   Operational 

G.     Does the system make maximum use of available resources, including people, time, flow of forms, minimum processing delays, and the like?   Operational

H.      Does management support the system?     Operational

I.        What is the net present value of the system?    Economical

J.        How will the working environment of the user change?     Operational

K.      How do the users feel about their role in the new system?  Operational

L.       Do we have the expertise to implement the solution?     Technical

M.    What is the payback period for the proposed system solution?      Economical

N.     Does the system provide users and managers with timely, pertinent, accurate, and usefully formatted information?  Operational

O.     What is the return on investment for the new system?     Economical

P.      Is the project deadline mandatory or desirable?   Schedule

Q.     Does the system provide desirable and reliable service to those who need it?    Operational

R.      Is the system flexible and expandable?    Operational

S.       Are the resource available in our data processing?     Technical

Sample Candidate System

·         Custom

·         Off the shelf

Feasibility analysis matrix   is a tool

We weight each of the of the types of feasibility in percentages and then sore each section

Net Payback Analysis

The time value of money recognizes that a dollar today is worth more than a dollar one year from now.

(Future) value (FV) of £1 in n years, at interest rate, i, can be described by the following equation.

FV =PV(1+i)ⁿ 

Where

FV = Future value

PV = Present value

n = Number of years

i = Interest rate (discount rate)

Example: Net payback analysis

The value of €500 after 2 years at an annual interest  rate of 6% would be:

FV =500(1+0.06)² = 500(1.236)=€561.80

Restating the above equation:

FV/(1+i)ⁿ =PV

FV x 1/(1+i)ⁿ = PV

Discount factor

Example: Net Payback Analysis

If you were offered €561.80 in two years time, 6%discount rate, what is the value today?

€561.80 x 1/(1+0.06)² = PV

PV = €561.80 X 1/(1.1236)

PV = €561.80 X 0.8899

PV = €500

The discount factor is always:

1/(1+i)ⁿ

The discount factor on a sum to be received a year from now (6%P.a)

1/(1.06)¹=0.94

Two years from now:

1/(1.06)²=0.889

ERD:  is an Entity Relationship Diagram

Focus on system data

DFD:  is a Data Flow Diagram

Focus on system processes

System Modelling

A model is a representation of reality

Logical models

Show what a system “is” or “does”. They are implementation- independent- illustrate the essence of the system

Physical model

Show what a system “is” or “does” and how  the system is physically and technically implemented- implementation-dependent

System Modelling

System analysis activites focus on the logical system models:

Logical models removes biases

Logical models reduce the risk of missing business requirements

Allow us to communicate with end users in a non-technical language

Data Modelling

Sometimes called data base modelling because a data model is usually implemented as a data base

The process of constructing data models helps analysis ans users quickly reach consensus on business terminology and rules.

Data Models are frequently referred to entity relationship diagrams (ERD)

Entities

All systems contain data-Data describes “things”

A concept to abstractly represent all instances of a group of similar “things” is called an entity.

An entity is something about which we want to store data.

E.g Persons, Places, Objects, Events about which we need to capture and store data.

An entity instance is a single occurrence of an entity

Attributes

The pieces of data that we want to store about each instance of a given entity are called attributes

Values for each attribute are defined in terms of three properties: data type, domain, and default

The data type for attribute:

E.g

Number   10-99

Text           max size 30

Date         mmddyy

The domain

The domain of an attribute defines what values an attribute can legitimately take on.

E.g

Number   integers- 10-99

Text          max size 30

Date        format-  mmddyy

The default value for an attribute is that value which will be recorded if not specified by the user

 E.g number = 0

Key

Hence every entity must have an identifier or key

Candidate Key: where an entity can have more than one –Key- each of these attributes is called a candidate key

Candidate Key: where a group of attributes is required to uniquely identifies an instance of an entity

DVD entity in video store

Title NO + Copy No

Primary Key

Is that candidate key which will most commonly be used to uniquely identify a single entity instance

Type ID (instance Primary Key)

Alternate keys

Are those not specified as primary keys

Customer Customer Number (PK) Customer Name Shipping address* Billing address* Balance due*

A primary key imported into order becomes a foreign key

Order Order number (PK) Order date Order total cost Customer number (FK)

                                                                                Has placed

 

*alternative keys

If I took customer name and customer number it would be a concatenated key

 

Ordered Product Order product ID (PK) Order number (FK) Product number (FK) Quantity ordered unit price

Inventory product Product number (PK) Product name Unit of measure Unit price

                                                                                Sold as 

 A Subsetting criteria

Is an attribute whose values divide all entity instances into useful subsets.

Need to identify all male students and all female students

Relationships

A relationship is a natural business association that exits between one or more entities

A connecting line between two entities on an entity relationship diagram (ERD) represents a relationship

A verb phrase describes the relationship

All relationships are implicitly bidirectional, they can be interpreted in both directions (binary)

Curriculum

Student

                                                                O  or more students

                                                          Is being studied by              is enrolled in     

                                                                                                                           1 or many

Cardinality

The complexity or degree of each relationship is called cardinality

Cardinality defines the minimum and maximum number of occurrences of one entity foe a single occurrence of related entity

E.g must there exist an instance of student for each instance of curriculum? No

Must there exist an instance of curriculum for each of students? Yes

3 important things in a ERD

1.       Attributes

2.       Keys (primary, alternate, foreign)

3.       Cardinality – show symbol and relationship E.g 1 to many

The degree of a relationship is the number ot entities that participate in the relationship

A Binary relationship has a degree = 2

Recursive relationship degree =1

An associative entity is an entity that inherits its primary key from more than one other entity (parents)

Foreign Keys

A foreign key is a primary key of one entity that is duplicated in another entity for the purpose of identifying instances of a relationship

A non –specific relationship (or many –to-many relationship) is one in which many instances of one entity are associated with many instances of another entity

JAD (joint application development) sessions

Facts collected by sampling existing forms and files; researching similar system; surveys of users and management

How to construct data models

Step 1 – Identify Entity

Entities should be named with nouns that describe the person, event, place, or tangible thing about which we want to store data.

Step 2 – Define keys for each entity

The value of a key should not change over the life time of each entity instance.

The value of a key cannot be null (entity integrity)

Step 3 Draw a rough draft of the ERD model

Step 4 Identify Data Elements/ Attributes

Step 5 Draw the Fully Attributed Data Model

Process Concepts & Conventions

Logical process are work or actions that must be performed no matter how you implement the system

Each process will be implemented as one or more physical process that may include:

·         Work performed by people

·         Work performed by robots / machines

·         Work performed by computer soft ware

Three types of logical processes: functions, events, and elementary process.

Functions

A function is a set of related and on-going activates of the business. A function has no start or end  it just continuously performs it’s work as needed.

Events

An event is a logical unit of work that must be completed as a whole

Elementary process

An event process can be further decomposed into elementary processes that illustrate in detail how the system must respond to an event

Three Errors with process

A black hole is when a process has inputs but no outputs. Data enters the process and then disappears

A miracle is when a process has output but no input

A grey hole is when the inputs of a process are insufficient to produce the output(most common)

Process modelling  

 A technique for organizing and documenting the structure flow of data through a system analysis /processes

A data flow diagram (DFD)/(bubble graph)

Process model consists of data flow depicts the flow of data through a system diagram and the work or processing preformed by the system.

As information moves through software , modified by series of transformations

Data Flow Diagram

Uses three symbols and one connection

What are the symbol of a DFD (data flow diagram)

Process

Rounded rectangle or circles represent process performs transformation on its input data to yield tis output data

Process

Process

 

External agents or external entity

Square represent External agents, a source of system inputs or a sink of system outputs residing outside system

Eternal Agent

1.       Data flows should not split into two or more different data flows

2.       Don’t  connect 2 exit entities NB don’t connect to data store

3.       Process need to have at least  one input data flow and one output data flow,

Data stores

Open ended boxes represent data stores, repository of data- never to be shown in a context diagram

Data Flows

Arrows represent data flows, to connect processes to each other

Rules for DFDs

1.       Each object must connect to at least one other process- objects is external entity, process, data store, data flow

2.       Each process must use at least one input data flow and produce one output data flow

3.       Each item in a process’s data flow must correspond or derive from the process’s input data flow

4.       Each data flow to or from a data store/ external entity must connect to a process. Maximum 7 process per DFD

Arrange process so that major data flow is from left to right

Process: verbs

Data flows: external entities; data stores: nouns

A Process

Is work performed on, or in response to, incoming data flow or conditions

Process Decomposition

When a complex system is too difficult  to fully understand when viewed as a whole (meaning as a single process)

System analysis separates a system into its component subsystems, which in turn are decomposed into smaller subsystem

Process abstraction

Process of reducing complexity by mapping details into one higher level concept, ie. A concept diagram

Never add data stores to a context diagram

Only one process, data flows and external entities are placed in a context diagram

Requirements-Gathering Techniques

Interviews

Most commonly used technique

Basic steps

·         Selecting interviewees

·         Designing interview questions

·         Prepare for the interview

·         Conducting the interview

·         Post-interview follow up

Selecting interviewees

·         Based on information needs

·         Best to get different perspectives

Managers

Users

Ideally, all key stakeholders

·         Keep organizational politics in mind

Designing interview questions

·         Unstructured interview useful early in information gathering

Goal is broad, roughly defined information

·         Structured interview useful later in process

Goal is very specific information

Preparing for interview

·         Prepare general interview plan

List of question

Anticipated answers and follow ups

·         Confirm areas of knowledge

·         Set priorities in case of time shortage

·         Prepare the interviewee

Schedule

Inform of reason for interview

Inform of areas of discussion

Conducting the interview

·         Appear professional and unbiased

·         Record all information

·         Check on organizational policy regarding tape recording

·         Be sure you understand all issues and terms

·         Separate facts from opinions

·         Give interviewee time to ask questions

·         Be sure to thank the interviewee

·         End on time

Post –interview follow-up

·         Prepare interview notes

·         Prepare interview report

·         Have interviewee review and confirm interview report

·         Look for gaps and new questions

Joint Application Development(JAD)

·         A structured group process focused on determining requirements

·         Involves project team, users, and management  working together

·         May reduce scope creep by 50%

·         Very useful technique

·         Quality : walkthrough, inspections, and formal technical reviews

JAD Participants

·         Facilitator

Trained in JAD techniques

Sets agenda and guides group processes

·         Scribe(s)

Record content of JAD sessions

·         Users and managers from business area with broad and detailed knowledge

Preparing for JAD sessions

·         Time commitment – ½ day to several weeks

·         Strong management support is needed to release key perticipants from their usual responsibilities

·         Careful planning is essential

·         E-JAD can help alleviate some problems inherent with groups

Conducting the JAD Session

·         Formal agenda and ground rules

·         Top- down structure most successful

·         Facilitator activities

Keep session on track

Help with technical terms and jargon

Record group input

Stay neutral, but help resolve issues

·         Post-session follow up report

Post JAD follow –up

·         Post session report is prepared and circulated among session attendees

·         The report should be completed approximately a week to two after the JAD session

Questionnaires

·         A set of written questions, often sent to a large number of people

·         May be paper-based or electronic

·         Select participants using samples of the population

·         Design the questions for clarity and ease of analysis

·         Administer the questionnaire and take steps to get a good response rate

·         Questionnaire follow up report

Good questionnaire design

·         Begin with nonthreatening and interesting questions

·         Group items into logically coherent sections

·         Do not put important items at the very end of the questionnaire

·         Do not crowd a page with too many items

·         Avoid abbreviations

·         Avoid biased or suggestive items or terms

·         Pre-test the questionnaire to identify confusing questions

·         Provide anonymity to respondents

Document analysis

·         Study of existing material describing the current system

·         Forms, reports, policy manuals, organization charts describe the formal system

·         Look for the informal system in user additions to forms /report and unused form /report elements

·         User changes to existing forms /reports or non-use of existing forms /reports suggest the system needs modification

Observation

·         Watch processes being preformed

·         Users/managers often don’t accurately recall everything they do

·         Checks validity of information gathered other ways

·         Be aware that behaviours change when people are watched

·         Be unobtrusive

·         Identify peak and lull periods

Selecting the appropriate requirements- gathering techniques

·         Type of information

·         Depth of information

·         Breadth of information

·         Integration of information

·         User involvement

·         Cost

·         Combining techniques

Reference information attained from course material