IB CS Paper 1

Reasons to implement a new system

• old system doesn’t achieve intended purpose

• old system is inefficient

• to increase productivity, efficiency, and/or quality of output

• to decrease system fans and costs

Features to Consider when implementing a new system

• User Role

• Resources appropriate for the organization

• costs/budget limits

• delivery time

• compatibility with the old system

Challenges of Changing a system

• User Response

• loss of old features

• data loss

• financial cost

• incompatibility between old and new system

Legacy System

Outdated system that still technically preforms function but is no longer supported, kept because modernization may be time-consuming

Merger

Combination of tow or more entities into one

Challenges of mergers

• Software compatibility

• convention differences

Software Types

• Local

• Remote

• SaaS

Software Type: Local

purchased and installed on a specific computer

Software Type: Remote

used through a browser

Software Type: SaaS

Third party companies host applications and let customers user them over the internet

Internet Features:

• Data is in the cloud/computing infrastructure

• software necessary for the activities in the cloud

  • client can access the software by web-browsing

Internet Benefits:

• Good for minimizing IT costs

• Good for small businesses (SaaS subscription can be adjusted at any time rather than paying for in-house server capacity and software licenses)

• Smaller staff workload because IT people don’t have to worry about n-side software and hardware tasks

• Backup: IT infrastructure is in the service providers data center

Internet Security Issues Storage

• Data is stored in the server of the service provider

• The organization can’t directly control its data

  • Provider may experience corruption, bankruptcy, or data loss

Internet Security Transmission Issues

• Applicants running in-site may require data in the SaaS, leading to longer transmission times and higher risk of failure, attack or interception

Installation Processes - Direct Changeover P/C

P: Done Quickly and easily, new system is available immediately

C: No fallback in case of failure because old system is no longer available

Installation Process - Parallel Changeover P/C

• P: There is a fallback; developers can make sure the new system works by comparing its outputs to the old system’s

  • C: Expensive and time consuming to run them both

Installation Process: Direct Changeover Definition

Old System is stopped and new system is started

Installation Process - Parallel Changeover

The new system is started and run alongside the old one for some time

Installation Process - Pilot Changeover Definition

The new system is piloted in a small part of the organization before being implemented widely

Installation Process - Pilot Changeover P/C

P: All featured are trialed before widespread implementation, only a small part of the organization suffers if something goes wrong, pilot staff can train new staff

C: No backup for the pilot group

Installation Process- Phased Changeover Definition

New system is introduces in phases to replace parts of old system

Installation process Phased Changeover P/C

p: People can get used to new system, staff can be trained in phases

C: No fallback in case of failture

Data Migration Definition

moving data between systems

Data Migration Problems:

• Incompatible file formats due to different versions

• Convention differences (data, currency, characters)

• Data Structure differences (moving from array to linked list)

• Validation rules from invalid inputs

  • Incomplete data transfer due to interruption

Types of Testing

• Static testing/Verification

• Dynamic Testing/Verification

• White-Box/ Structure Testing

• Black-Box/functional testing

• Beta testing

• Alpha testing

• User Acceptance Testing

• Automated Testing

Types of Installation process

• Direct Changeover

• Parallel Changeover

• Pilot Changeover

  • Phased Changeover

Static Testing/Verification

Using tools to analyze/check software without executing it

Dynamic Testing/Verification

Executing software and observing output based on test cases

Black-Box/Funcational Testing:

Tests software without knowing its internals, uses software interfaces to ensure they work out as expected

Beta Testing:

Preformed by end users at the client location in the last stage of development to test the functionalist of the system

Alpha Testing:

Preformed by internal employees at developer’s site

User Acceptance Testing:

Testing a system with end users to see if they are satisfied

Automated Testing

Using special software tools to control execution of tests and compare actual results with predicted results, usually too difficult to preform manually

User Documentation

Material that explains how to use the features and functions of a system to end users (books, pdfs, websites, videos, etc…)

User Documentation should:

Ensure users are aware of all features of a system and how to use them

Relatively simply but high quality, simple documentation - quick implementation

User Documentation Examples:

Help Files, Online Support, Printed Manuals

User Documentation - Help Files Definition

filed supplied within the system

User Documentation Online Support Definition

special web service hosted by the system developer

User Documentation : Printed Manuals Definition

Manuals printed on paper and supplies with the system

User Documentation - Help Files - P/C

P: Always accessible give instructions on how to use the system and address only major errors

C: Only usable after system implementation, only address general errors, no search capability

User Documentation - Online Support P/C

P: More extensive than help files, regularly viewed and updated, live support option, search capability

C: Requires an internet connections, requires users to be familiar with computers

User Documentation Printed Material P/C

p: can be read through before using the new system, always available, can help with installing the system

C: physical (can be lost, misplaced, limiting in number), limited information provided outside of system installation, not updated alongside the system

Methods of User-Training

Self-Instruction, Formal Classes, Remote Training

Method of User Training - Self Instruction Definition

reading a manual, watching a tutorial

Method of user training - Formal Classes Definition

a live instructor explains and shows how to use the sys

Method of User Training - Remote Training Definition

An instructor trains users through a remote connection

Method of User Training - Self Instruction - P/C

P: Cheapest, flexible timeline, tailored to what users want to learn

C: no interactive guidance, unstructured (certain features can be overlooked)

Method of user training - Formal Classes P/C

P: structueed living environment, expert to answer specific questions, curriculum design to teach all aspects of the program

C: Expensive, rigid structure, and curriculum, not much personalization

Method of User Training - Remote Training P/C

P: same as formal classes

C: requires an internet collection, no hands-on, computer-based