An embedded system This is a system where the software controls a hardware device and is embedded in that device. Issues in embedded systems typically include physical size, responsiveness, power management, etc. The example software system to control a medical device
An information system This is a system whose primary purpose is to manage and provide access to a database of information. Issues in information systems include security, usability, privacy, and maintaining data integrity. The example a medical records system.
A sensor-based data collection system This is a system whose primary purpose is to collect data from a set of sensors and process that data in some way. The key requirements of such systems are reliability, even in hostile environmental conditions, and maintainability. The example a data collection system at a wilderness weather station.
Systems for modeling and simulation These are systems that are developed byscientists and engineers to model physical processes or situations, which nclude many, separate, interacting objects. These are often computationally
intensive and require high-performance parallel systems for execution
Interactive transaction-based applications These are applications that execute on a remote computer and that are accessed by users from their own PCs orterminals. Obviously, these include web applications such as e-commerce applications where you can interact with a remote system to buy goods and services.This class of application also includes business systems, where a businessprovides access to its systems through a web browser or special-purpose clientprogram and cloud-based services, such as mail and photo sharing. Interactive applications often incorporate a large data store that is accessed and updated in each transaction
Batch processing systems These are business systems that are designed to process data in large batches. They process large numbers of individual inputs to create corresponding outputs. Examples of batch systems include periodic billing systems, such as phone billing systems, and salary payment systems
Data collection systems These are systems that collect data from their environment using a set of sensors and send that data to other systems for processing. The software has to interact with sensors and often is installed in a hostile environment such as inside an engine or in a remote location

1.1.1 Identify the context for which a new system is planned

Teacher Notes

Before a system is designed, it needs to be identified what the system should do. To do this is the job of the systems analyst. He looks at the existing system and tries to observe how it works. This can be done using surveys, interviewing users, observing them or by tracing how information is handled by looking at the documents produced by it.

For this, the systems analyst has to factor in a number of things: what existing infrastructure from the existing system can be used? What requirements on hardware and software will the new system have? Are there any ethical issues resulting, for example will the new system make people unnecessary, leading to loss of jobs?

Data Collection

Questionnaires
Interviews
Observation
Current system documentation
User manuals

1.1.2 Describe need for change management

Teacher Notes

Without a proper plan on how the new system will be implemented once it is designed the change from the old system to the new one will not be successful. Many factors will need to be regarded:

End user training
User's reluctance to change
User acceptance testing
Type of change over ?

1.1.3 Outline compatibility issues resulting from situations including legacy systems or business mergers

Without a proper plan on how the new system will be implemented once it is designed the change from the old system to the new one will not be successful. Many factors will need to be regarded:

1
Legacy System – In computing, a legacy system is a technology, computer system, or application program, that may or may not be supported or available for purchase any more.
2
Merger – A combination of two things, especially companies, into one

Language differences
Part of business operating in a different country than host using an older version of a system
If an american and an European businesses merge, their unit systems need to be merged (one uses SI units, one doesn’t)
Businesses not using same software environment (Microsoft Exchange vs. IBM Lotus Notes)

1.1.4 Compare the implementation of systems using a client’s hardware with hosting systems remotely.

Software as a Service (SaaS): The client does not run its own computer system to handle operations, but lends servers from the software manufacturer that are managed and maintained by the software manufacturer. A great example is SAP.

Advantages

No cost in employing personnel to maintain system
Software manufacturer can provide help in cases of malfunction
Maintenance and updating managed by software manufacturer → they have staff that fully understand the system
Client enjoys the professional know-how of the software manufacturer

Disadvantages

Data security issues resulting from trusting your information to someone else (loss of control)
Host may be in a different time zone, so maintenance can happen at uncomfortable times
Because host is not the user itself, user feedback is harder to get

1.1.5 Evaluate alternative installation processes.

Teacher Notes

Direct changeover / Big Bang
Parallel running
Phased Changeover
Pilot running

1.1.6 Discuss problems that may arise as a part of data migration

Teacher Notes

File formats are another worry when concerning the issue of data migration and compatibility. Having the ability to read and write data in the same manner as before, following an improvement or change in a system, is almost certainly the fundamental aspect which is taken into consideration.

Incompatible file formats

Incompatible data structures

Changed units leading to misinterpretation (new system interprets temperature in °C instead of °F)

1.1.7 Suggest various types of testing.

Teacher Notes

esting is very important in developing a computerized system, as it tries to ensure that the system works as expected. A system that does not work as expected (it is buggy) greatly reduces productivity and end user satisfaction.

Testing is usually done in two stages: before the system is delivered and after it has been set up.
Testing in the first stage is often referred to as Alpha testing, while testing in the second stage is often referred to as Beta testing.

Alpha testing involves the engineers who develop the system testing it with data similar to real data while beta testing involves testing by real users with real data.

Unit Testing
Alpha Testing
Beta Testings
Integration testing
user Acceptance Testing

1-1-7_testing

User focus

1.1.8 Describe the importance of user documentation.

Teacher Notes

User documentation is a crucial part of a system as it is the document that explains the working of the system to the user. A well-made user documentation guides the user through using the system and thus increases productivity. If the user documentation is simple, system implementation can happen faster because users require less training to learn how to use the new system.

Users are non-technical people, they only need to know how to use the system. Therefore, the user documentation does not involve detailed explanations of how the system works.

User documentation supports computer system users, including both hardware and software. Good user documentation can ensure that users are quickly able to adapt to a new system. Documentation is an important part of software engineering. Types of documentation include:

Different Types

Requirements - Statements that identify attributes, capabilities, characteristics, or qualities of a system. This is the foundation for all that is implemented.
Architecture/Design - Overview of software. Includes relations to an environment and construction principles to be used in design of software components.
Technical - Documentation of code, algorithms, interfaces, and APIs.
End User - Manuals for the end-user, system administrators, and support staff.

1.1.9 Evaluate different methods of providing user documentation.

Teacher Notes

Help files: Files supplied together with the system. They can usually be called up with a button in the system.

Advantages

Accessible at any time when using the program
Give general instructions on how to use the system
Give general instructions on how to solve some major errors

Disadvantages

They can only be used after system has been installed. They don’t give any help when installing the solution
They often only deal with very general errors
They often lack a search capability, you have to look to find help for your problem

Online support: Special web service hosted by the system’s developer to provide user documentation.

Printed manuals: manuals printed on paper and supplied together with the system.

1.1.10 Evaluate different methods of delivering user training.

Training staff in using a new system is very important as productivity greatly depend on how familiar users are with a system. Therefore good user training is an essential part of introducing a new system.

Self-instruction: users reading a manual or watching a tutorial, or randomly doing something in the system to figure out how it works. This type of training is only suitable for experienced computer users as they are more confident to start using an unfamiliar system alone to figure out how it works.

Formal classes: users sitting in a classroom listening to an instructor who shows and explains how to use the system. This type of training is useful to train large amounts of staff as it is effective and relatively cheap, but if the size of the classes is too big, there is little time to deal with individual problems and questions.

Remote/online/personal training: an instructor training a single user either by being in the same room or by some kind of remote connection (Skype, chat). This is the most effective way of training as training can be suited to user’s needs and abilities, but is very expensive compared to other types of training.

System Backup

1.1.10 Common Causes of Data Loss

Human Error
Viruses & Malware
Power Outages
Software Corruption

Computer Theft
Liquid Damage
Software Corruption
Hackers and Insiders

1.1.12 Outline the consequences of data loss in a specified situation.

Data Loss in School

If a school loses its online information, it can lose schedules, grades, personal information about who works there and who studies there, and future plans for the school.

1.1.13 Describe a range of methods that can be used to prevent data loss

1.1.12 Outline the consequences of data loss in a specified situation.

Software Depolyment

1.1.13 Describe strategies for managing releases and updates

Students should be aware of a variety of ways in which updates and patches are made available and deployed. This includes automatic updates received on a regular basis online

1.1.13 Describe strategies for managing releases and updates

1.2 System design basics (10 hours)

Components of a computer system

1.2.1 Define the terms: hardware, software, peripheral, network, human resources.

1.2.2 Describe the roles that a computer can take in a networked world

1.2.3 Discuss the social and ethical issues associated with a networked world.

System design and analysis

1.2.4 Define the terms: hardware, software, peripheral, network, human resources.

1.2.5 Describe methods of obtaining requirements from stakeholders.

1.2.6 Describe appropriate techniques for gathering the information needed to arrive at a workable solution.

1.2.7 Construct suitable representations to illustrate system requirements.

1.2.8 Describe the purpose of prototypes to demonstrate the proposed system to the client.

1.2.9 Discuss the importance of iteration during the design process

1.2.10 Explain the possible consequences of failing to involve the end-user in thedesign process.

1.2.11 Discuss the social and ethical issues associated with the introduction of new IT systems.

Human interaction with the system

1.2.12 Define the term usability.

1.2.13 Identify a range of usability problems with commonly used digital devices.

1.2.14 Identify methods that can be used to improve the accessibility of systems.

1.2.16 Discuss the moral, ethical, social, economic and environmentalimplications of the nteraction
between humans and machines.

SDLC Lesson Overview

Systems Development Lifecycle

Building a house

Investigation/Feasibility study

Investigate systems currently being used - benefits/limitations

requirements for the new system

Create report on

Purpose of the new system

System scope/what it will cover

Deficiencies in the current system

User requirements

Costs and benefits of the new system

Investigate

What kind of house is needed?

How will the house be used (family, young couple, retired, young single)?

How big is the plot of land?

Does the land have Gas. Water, electric?

What rooms/levels are required?

Likely cost to build the house

Benefits of the house

Analysis - Detailed User Requirements

Detailed list of

Input requirements

Output requirements

Processing and calculations required

Detailed requirement list

Rooms

Size of rooms

Requirements in each room

Type of building

Design the Systems

Work out:

Data Flow Diagrams

Entity Relationship Diagrams

Attributes

Data Dictionary

Program Specifications

Design the House

Work out:

House plan

List of parts required

Plan build of house, what needs to be done in what order

Develop the system

Write the programs according to the design

Build the house

Build the house according to the house plans and project plan

Test the system

Functional test

test each program

System test

Test programs link together correctly (whole system test)

Make sure everything works in the house

Test wiring and electrics

Test plumbing

Test heating

Test appliances in the kitchen

etc

System Documentation

Produce:

Technical Documentation

User Documentation

House Documentation

Land registry documents

Contract on sale of house

Searches

Instructions on central heating/appliances

Systems Implementation

Train the users in how to use the system

Hand over the system to the users

New Owners move into the house

Maintenance - Monitor & review

Make sure system is running okay

Report and fix any bugs in the system

On Going Maintenance

Report any problems back to the builder

Builder fixes problems

Lesson 1( 1.1.1 -.1.1.3 ) ( SDLC )

Learning Objectives

Overall understanding of the SDLC Stages
Understand Purpose and methods of data collection
Understand the need for change management
Understand the choice between bespoke / off the shelf and SaaS
Understand the meaning of a legacy system

Google Doc explaining the different stages of SDLC - Open and Take copy clicking here

Lesson 1 Class Activity

Select a real life example from the list of software system types below that has been a disaster.

Provide a brief overview of the disaster and the reason why it was a disaster. You will report your findings in the next class.

An embedded system (This is a system where the software controls a hardware device and is embedded in that device.)
Off the Shelf
Transactional ( web applications such as e-commerce applications where you can interact with a remote system to buy goods and services.)
Modelling / Simulation
Information system (primary purpose is to manage and provide access to a database of information. )
Batch processing ( Billing / payroll )
Data Collection system / A sensor-based data collection system ( example gathers data from environment )

Lesson 2 ( SDLC )

Learning Objectives

Overall understanding of the SDLC Stages
Understand and rank the key methods of data Collection
Compare the implementation of systems using a client’s hardware with hosting systems remotely.

Review Questions

When an organization needs new software what are the main options available ?

Link to power slide

Lesson 3 ( testing ) ( SDLC )

Learning Objectives

Understand the difference between Beta and Alpha testing
Appreciate the waterfall approach has faults
Understanding of other more agile approaches

Review so far

1
Legacy System – In computing, a legacy system is a technology, computer system, or application program, that may or may not be supported/available for purchase any more.
2
Merger – A combination of two things, especially companies, into one

Activity 5-10 min Class discussion on advantage and disadvantageous of

1 off the shelf software and

2 Custom / Bespoke S/W

Task find a SW disaster and share with class 5 mins

Stage 1 Analysis and User Requirements

Questionnaires
Interviews
Observation
Current system documentation
User manuals

What is the output of this stage ?

What is the big weakness in the waterfall method to s/w development?

Waterfall - Sequential flow in one direction thus waterfall. In real life failures to correctly capture user requirements can be a disaster as the costs to change after the coding / development has started is huge

Incremental Models

First step create part of the system with limited functionality. Example in patients record system first step provide view only access to patient records.

Stage 2 Add Amend update

Open Source would be a good example of the incremental approach

Iterative Model

First step show interface to system options available reports etc ( do not add the actual functionality until end user approved). We are therefore clarifying the user requirements.

The user can request change with minimal additional time and cost being added to overall project budget

What is prototype ?

Similar to Incremental

Agile Approach

Implementation

Direct changeover / Big Bang
Parallel running
Phased Changeover
Pilot running

We have discussed off the shelf S/W and Bespoke

We have looked at these stages in the waterfall methodology

1 )Systems Analysis and defining user requirements ( Methods of data gathering).

2 )Approaches to setting the system live.

Without a proper plan on how the new system will be implemented once it is designed the change from the old system to the new one will not be successful. Many factors will need to be regarded:

End user training
User's reluctance to change
User acceptance testing
Type of change over

Lesson 4 Overview ( SDLC )

Learning Objectives

Learning with Flash Cards Click Here
Why Projects Fail Review Real Failure Click here
Overview SDLC click here

The Systems Analyst Ethics

Lesson 5 ( User Focus Documentation and Training )

Learning Objectives

Describe the importance of user documentation
Evaluate different methods of providing user documentation
Evaluate different methods of giving user Training

LInk to slide Show click here

Review Unit Test Past Papers

resources

Information Technology in a Global Society IB

Review Click Here

Complete

Legacy System Definition

A legacy system is a computer system that is no longer available for purchase or is no longer supported by the manufacturer. A legacy system might be just a few years old, or it could be decades old. Some legacy systems may operate on (and even require), certain very old hardware which is no longer available. Others may only run on older operating systems and not be compatible with modern versions. Sometimes the manufacturer of a legacy system no longer exists, and in other cases the manufacturer has dropped support in favour of more recent products. This usually means updates and security fixes will not be available for the system, which can be a significant problem for organisations.