systems analysis and design

SYSTEMS ANALYSIS AND DESIGN

Presentation by:Walter Onditi

Perpetua MugerekiEunice NgunjiriSammy Nyambu

William Turi

Software Acquisition Installation Implementation ActivitiesPost ImplementationSoftware Support and Maintenance

Topics Covered

SOFTWARE AND ACQUISITION

Evaluating and Purchasing Software Packages

Examine software alternatives and select an overall strategy for the proposed System to prepare for the transition to the systems design phase.

Process• Step 1: Planning the acquisition eg Assigning Key Roles• Step 2: Defining the software product’s requirements i.e

the software requirements are elicited, analyzed, specified and validated .

• Step 3: Determining the acquisition approach • Step 4: Identifying and evaluating potential suppliers (and

their software products) eg Formal Request-For-Proposal (RFP)

• Step 5: Defining the contract requirements eg Fixed-Price Contracts, Cost reimbursable contract

• Step 6: Selecting a supplier eg Cost/Benefit Analysis,• Step 7: Negotiating and awarding the contract eg Risk

Sharing:

Plan the Acquisition

Software development

Determine Acquisition Approach

Select a Supplier

Manager Supplier

Accept Product & close Contract

Build

Buy

Define the Software Product

Define Contract Requirement

Identify & Evaluate Potential Supplier

Negotiate & Award Contract

Process Cont---

METHODS OF ACQUIRING SOFTWARE

Custom Developed Software In-house Development. Contract an External Software –

Advantages of Custom Developed Software

Resultant program will exactly fulfill the processing requirements.

Disadvantages of Custom Developed Software

Higher Cost eg Cost borne by one organization than being shared

Software Defect

In-House Developing

Companies choose in-house development to:

Satisfy Unique Business Requirements

Minimize Changes in Business Procedures and Policies

Meet Existing TechnologyDevelop Internal Resources and

Capabilities

Package Purchasing – Off-the self Packages

A commercially available software package could satisfy system requirements.

Advantages• Lower Cost• Less Time to Implement• Proven Reliability and Performance Benchmarks• Less Technical Development Staff • Future Upgrades Proved by the Vendor • Other Companies as Resources• Better Documentation• Training Easily Available• Disadvantages of Packaged Software• May not meet all requirements• Less efficient•

Customizing Software Packages

Acquire a package that can be customized to meet the needs of an organization.

-Purchase a basic package that vendor will customized to suit your needs

Negotiate directly with the software vendor to make enhancements to meet your needs by paying extra charge

Purchase the package and make your own modification.

In-House developed vs Purchased Package

Other Software Alternatives

Other possibilities include using :• An application service provider - An ASP

delivers applications, or access to applications, by charging a usage or subscription fee , license (Application Hosting)

• Outsourcing - is the use of outside companies Called Service Providers to handle a portion of a company’s IT workload on a temporary or long- term basis.

• Developing end-user applications - utilize standard business software, such as Microsoft Office, which has been configured in a specific manner to enhance user productivity.

Disadvantages of Outsourcing

• Could lose control over the software, risk is high due

to competition

• Do not build internal competence

• Development costs could exceed the budget

• Time schedule could be overrun

• The outcome might not meet expectations

• Some projects could be canceled before end of

development period

• Customer might not take active part in development

Recommended Software Acquisition Best Practices

Best Practices DescriptionContractor capability evaluation Performing a formal evaluation of the contractor's

software development capability as part of source selection

Contractual software process commitment Obtaining a contractual commitment that the contractor will follow mature, well-disciplined software engineering processes

Independent technical reviews Performing independent technical reviews of the contractor's software products and processes throughout the development life cycle

Realistic cost and schedule constraints Imposing realistic software cost and schedule constraints based on valid historical data and appropriate use of software cost models

Software acquisition metrics Using metrics as an integral part of the Government's software acquisition processes

Software acquisition process improvement Analyzing current software acquisition processes for deficiencies and implementing new/modified processes to correct those deficiencies

Software acquisition risk management Using a continuous process of software acquisition risk identification, assessment, prioritization, mitigation, and control throughout the system life cycle

Software quality incentives Using award fees and other incentives to positively motivate the contractor to use software engineering best practices

Software system acquisition Including software as an integral part of the systems acquisition processes

Software-inclusive performance requirements Including software in the specification of system performance requirements

System Installation

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Installation is the setup or making the system ready for execution and available for users.

Systems often come with a specialized program for installation referred to as installer

Systems can be installed from a storage media (CD/DVD or flash drive), or from a network.

Types of installationAttended installationAn installation process that needs a user who attends to it in order to make choices, such as accepting or declining EULA (end-user license agreement ) and installation locationOften uses wizard-based interface installers may ask users to help mitigate the errors E.g. if the installation disk chosen is full, the user is asked to specify another target path.

Unattended installationInstallation that is performed without user interaction during its progress It does not require the user to supply any informationThey use an answer file, a file that contains all the necessary parameters prior to the start of installation.

There is no user to help mitigate errors so if the installation medium was faulty, the installer stops the installation and may record errors in a computer log for later reviewSilent installationInstallation that does not display messages or windows during its progress. Done for convenience or subterfuge (Deceit )E.g. Malware is always installed silently when a user plugs in an infected device

Scheduled or automated installationAn installation process that runs on a preset time or when a predefined condition is met E.g. installations of updates when the machine is idle or weekly antivirus updates Clean installationDone in the absence of any interfering elements such as old versions of the computer program being installed or leftovers from a previous installation.

Activities during Installation Recommended system

requirements: certain hardware components or other software resources that have to be present on a computer

Checking for existing versions of the software

Creation of Shortcuts or links; Making the software accessible to user with minimum clicks

Performing product activation

• Before implementing, it is necessary to Develop a test System that fulfils business and design requirements

• This test system implements the interfaces between the new system and existing systems.

• This is referred to as Construction phase

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If system calls for new network functionality, then it must be built and tested first

The Network designer – designs LANS and WANS and tests the connectivity

The Network administrator – takes care of the network security

Systems analyst Ensures that business requirements are not compromised i.e. ensures that Standards are met

Activities Involved

Test with sample data System users

Provide test data Database designer/programmer

Build tables, views, stored procedures (if relational database)

Database administratorManipulate the database for optimum performance

Deals with SecurityBackup and recovery

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Creation and Testing of databases

Installation of New Software Packages

Some Systems solution may require purchase or lease of software packages

Involves System users, analysts, designers, builders, vendors and consultants

Testing New Packages An investigation conducted on a

system to evaluate the its compliance with its specified requirements.

Its is done to confirm that all modules work as specified, and as a system as a whole .

Testing is done after entire program is written

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Stub test - done on individual events or modules of program to simulate the behaviors of software components• Unit test - This is done on modules

coded & stub tested for a program and tested as integrated unit.

• Systems test -This ensures that separately developed and tested modules can properly when integrated into total system

Testing levels

IMPLEMENTATION ACTIVITIES

INTRODUCTION• Once a new system has been

designed, it must be implemented as a working system and maintained to keep it operating properly.

• Many implementation activities should be undertaken in parallel to reduce implementation time. Training of personnel and preparation of software may be in parallel with each other and with other implementation activities.

Implementation

Planning the implementation

Phase 1: PreparationPhase 1: Preparation•Identify project manager, administration & other key team members•Review technical requirements with IT•Training for Administrators

Phase 2: Set UpPhase 2: Set Up•Configure general site information•Customise branding•Set Session defaults•Customise email templates•Add users

Planning the implementation

Phase 3: Roll OutPhase 3: Roll Out•Training session leaders•Activate all user accounts•Users to create/conduct private sessions•General Question & Answer Sessions•User start conducting live sessions

Phase 4: Follow upPhase 4: Follow up•Monitor usage-Ongoing•Hold follow up meetings-Ongoing

Implementation phase

System conversion Strategies

Once the design has been completed, there are four basic methods for implementing the information system. Parallel conversionOld & new system run simultaneously until end users and project coordinator are satisfied that the new system is functioning correctly. It can be effected by using;– a single cut over (predetermined date) or – phased cut over (predetermined method).

Outputs are compared from both systems for convergence and accuracy. It has low risk but high cost.

.


Direct Conversion/Slam dunk/cold turkey strategy/abrupt cut overHere, old system/method is switched off; new method is switched on. It has the least costs but has high risk of failure. It’s the only viable solution in activating new systems where two systems cannot co-exist

Pilot/Locational ConversionThe new system is installed in multiple locations such as branches from geographic perspective. It allows for direct or parallel methods to be used at a single location. It offers the best representation of organization. It is less risky and allows for evaluations before rolling out to different locations.


Phased/Staged ConversionPhased/Staged ConversionThis is an increamental approach. The new system is brought as a series of functional components that are logically ordered to minimize disruption to end users and flow of business. It takes a lot of time, less risky and is the most disruptions to organizations over time. Small parts or subsystems are substituted for the old. In the case of upgrading old systems, this may be a very desirable method.

Implementation Tasks

Post Implementation

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What is Post Implementation Review [PIR]o A Post-Implementation Review (PIR) is an assessment and review of the

completed working solution. o It will be performed after a period of live running, some time after the

project is completed.

Why conduct a PIR?o To ascertain the degree of success from the project, in particular,

o the extent to which it met its objectives, o delivered planned levels of benefit, and o addressed the specific requirements as originally defined.

o To examine the efficacy of all elements of the working business solution to see if further improvements can be made to optimize the benefit delivered.

o To learn lessons from this project, lessons which can be used by the team members and by the organization to improve future project work and solutions.

Post-Implementation Review

Issues

Time

PIR

Go Live

InitialTrouble-shooting

SettlingDown

FinalImprovements

FineTuning

When to conduct the PIR?o A Post-Implementation Review should be scheduled some time after the solution

has been deployed. o Typical periods range from 6 weeks to 6 months, depending on the type of

solution and its environment.o The PIR is intended to be an assessment and review of the final working solution.

There should have been at least one full processing and reporting cycle completed.

o It should not be performed while the initial snags are still being dealt with or while users are still being trained, coached and generally getting used to its operation.

Note:The PIR should be timed to allow the final improvements to be made in order to generate optimum benefit from the solution. There is no point in waiting too long as the results are intended to generate that final benefit for the organisation and team

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Post Implementation Who should conduct the Post Implementation Review [PIR]o Under normal circumstances, members of the project team will want to complete

the review as a natural extension of their responsibility to deliver optimum benefit from the solution.

o The argument is that they understand o what was required, o what was changed, o how it was achieved, o how things are supposed to work, o how to fix problems,

o However another school of thought will argue that that the review should be performed by an independent team.

o This reduces the risk that any errors or omissions of the project team might equally be overlooked in their review.

What Do you think??????

A solution is to do both. An independent audit team, working in consultation with the business users and project team, could examine whether the results are satisfactory.

The project team might then reconvene to consider that input and also to examine how to generate further value from the solution.

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How to conduct the PIR A list of points should be drawn up to cover all elements of the operational

solution including:- Current situation

Is the required functionality available? Have users received adequate training and coaching to take advantage of the new facilities? Are staffing levels and skillsets appropriate for the actual workloads? Are third parties such as customers and suppliers satisfied with the service? Are faults handled at an acceptable speed and with satisfactory results? Is data integrity being maintained within the system and in relation to other integrated or interfaced systems? Does the system and its usage meet current legal and regulatory requirements? Does the system have the capacity to deal with the actual peak loadings as encountered and foreseen?

Benefits What were the final costs of the project? What is the actual operating cost of the new solution? What is the actual benefit being delivered by the new solution? How does that compare to the original project definition?

Future improvements Could further training or coaching improve the degree of benefit being generated? Are there further functional improvements or changes that would deliver greater benefit? Are specific improvements required in procedures, documentation, support, etc? What learning points are there for future projects?

These questions will be investigated through a combination of investigative techniques including

interviews, examination of documentation, performance statistics, hands-on tests and checks,

Implications and potential remedial options would then be assessed and evaluated.

The findings and recommended actions would be prepared, normally in the form of a report or presentation.

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Post Implementation

Next Steps The findings and recommendations will be

presented to:1. the solution's business owners, 2. the leading participants in the project, and3. other parties who may be concerned with the results.

Specific actions should be proposed to address any further work that is recommended. This might be handled in several different ways, for example:

1. as routine support and maintenance, 2. as remedial work to be performed by the original project team,3. for line management to address through user education and procedures

etc,4. as further phases of development involving new projects.

SUPPORT AND MAINTENANCE

ICT SupportICT support entails the following four broad categories of activities under which certain events fall.ICT support services and acquisition of ICT systems •Determine customer requirements for ICT systems and support services •Evaluate available ICT systems and services against customer requirements •Prepare and present suitable options for the acquisition of ICT systems and support services •Develop plans to ensure that the ICT infrastructure delivers the required functionality, capacity and level of support

Customer Support Provision•Provide technical information and support in response to customer requirements•Identify potential improvements in the customers’ use of resources•Assist in reviews to identify how automated procedures may improve customers’ use of resources•Create route automated procedures and assist in the creation of complex automated procedures

Cont…

Install and Configure Equipment and Operating Systems•Prepare hardware/equipment for installation•Install and configure hardware/equipment•Test installed hardware/equipment•Prepare, carry out and document the installation and upgrade of operating systems•Configure and test installed operating system

Maintain Equipment and Systems•Identify hazards and reduce risks to health and safety•Identify hazards and reduce risks associated with electrostatic discharge•Apply, check and record preventative maintenance procedures on hardware/equipment in ICT systems•Identify failures with hardware/equipment in ICT systems•Apply, check and record remedial maintenance on hardware/equipment in ICT systems

ICT-Maintenance• ICT-Maintenance is considered as the set of all actions

which have as an objective to retain an item (or the whole system) in, or restore to, a state in which it can perform the required function. The actions include the combination of all technical and related administrative, managerial, and supervisory actions such as tests, measurements, replacements, adjustments and repairs.

Why Maintenance is Important• In the software lifecycle, nearly 70% of the cost goes

into Support & Maintenance activities of the application. Enterprises & Medium Sized Companies spend an average of 73% of their IT budget on Maintenance of existing systems.

FORMS OF MAINTENANCEPreventive maintenance •Keeping equipment and facilities in satisfactory operating condition by providing for•systematic inspection, detection, and correction of incipient failures either before they•occur or before they develop into major defects.•Maintenance, including tests, measurements, adjustments, and parts replacement,•performed specifically to prevent faults from occurring.•Preventive maintenance is usually done in regular time intervals (according to each item’s specifications). Ad-hoc preventive maintenance is performed after new software product releases or versions, if they are recommended for bug fixing. Some examples of preventive maintenance include:•Measurement of system’s performance and appropriate tuning•Virus scanning•Active directory scanning•Data volume control and compression (if applicable)•Data archiving / purging•Hard discs bad blocks detection and replacement

Corrective Maintenance•This form of maintenance aims at restoring the defective item(s) to the required state.•It is required after the occurrence of a problem or failure, hence the response time of the contractor or the overall availability of the system and its elements are essential indicators and terms in a maintenance contract.

Adaptive Maintenance•This form focus in adjusting a software product to properly interface with a changing environment.•It is required mostly in unstable legislative, institutional and/or technical environments. It is performed ad-hoc, in accordance with the frequency the environment changes.

Cont……Perfective Maintenance•This form of maintenance refers to enhancements to the product in order to either add new capabilities or modify existing functions.

•Perfective maintenance is normally part of a successful system’s life cycle, and refers to further extensions and improvements beyond the initial specifications. It may include the implementation of new software modules and/or new OS and off-the-self software versions which aim in performance improvement. In some cases, additional hardware is required to improve system security and performance.

How to carry outPreparing

Since the Organization may possess information systems and tools purchased from different vendors in a long time period, an efficient recordkeeping of the systems in hand is essential for maintenance management; hence performing a hardware, software and telecommunications inventory is the first step of an efficient maintenance program. Appropriate maintenance of the records and transaction monitoring result to keeping the information up-to-date, which in turn allows statistical data extraction to be used as input to further consideration about system maintainability, sustainability and related costs.

Obtain a good and detailed system documentation

A well-documented system (covering the entire architecture as well as all of its elements) is very important, especially for software maintenance. Furthermore, an updated documentation, reflecting the changes derived from the maintenance activities, should be provided for future purposes. Good documentation aims in providing structured instead of unstructured maintenance.

Prioritizing needs

Maintenance costs are a significant part of the system’s total life cycle costs. Therefore, revision of the business non-functional requirements (such as availability, performance etc) for each part of the system is essential before any signing a new maintenance contract in order to keep Organization’s costs within affordable barriers.

Cont….Contracting

Maintenance contracts may be signed with the ICT providers who supplied the equipment/ICT system or third parties who are in possession of the appropriate infrastructure. Increasing the number of contracts and contractors increases complexity and may cause administrative problems; hence it is advisable to review and consolidate maintenance contracts regularly, possibly achieving significant cost reductions as well.

Important parts of the planning activities are the hardware, software, data and telecommunication inventories.

Typical problems with maintenance include:•Inadequate documentation of system design and structure•Loss of "cultural" knowledge of system due to staff turnover•Lack of allowance for change in original software design•Inconsistencies between new software versions/releases and the existing•applications/tools.

Cont….

ICT systems’ maintainability is enhanced by:•robust initial design and understandable system/software structure•comprehensive and accurate documentation (including design documents)•use of standards (design, language, coding, etc.)•availability of extensive test cases