IMS3230 - Information Systems Development Practices
Quality and productivity issues in information systems development:
RAD, application packages, outsourcing
Semester 2, 2005
10.2
References
HOFFER, J.A., GEORGE, J.F. and VALACICH (2001) 3rd ed., Modern Systems Analysis and Design, Prentice-Hall
Chapter 19 AVISON, D.E. & FITZGERALD, G. (2003). Information
Systems Development: Methodologies, Techniques and Tools. (3rd ed), McGraw-Hill, LondonChapters 6.4, 22.1, 22.3, 22.4, 8
10.3
Quality and productivity
“solutions” include: user participation JAD (Joint Application Design) prototyping automated and other tools RAD (Rapid Application Development) Application packages outsourcing reuse
10.4
Rapid Application Development (RAD) :
A systems development methodology created to radically decrease the time needed to design and implement information systemsE.g. James Martin (1991)
RAD methodology
Rapid Application Development (RAD)
10.5
Rapid Application Development (RAD)
RAD claims to offer: a development lifecycle for much faster systems
development better and cheaper systems more rapid deployment of systems as developers and users
work together in real time
RAD relies on: extensive user involvement JAD sessions Prototyping I-CASE tools (integrated CASE tools) Code generators
10.6
Evolution of RAD:
Pressures for businesses to speed up and compete in a changing, global environment
Diffusion of high-powered prototyping and CASE tools:Why wait 2 or 3 years to develop systems likely to be obsolete upon completion?
Rapid Application Development (RAD)
10.7
James Martin’s four pillars of RAD:
Tools People Methodology Management
Rapid Application Development (RAD)
10.8
Tools: I-CASE tools with prototyping and code
generation facilities, Visual development environments
People: Manager and user participation in JAD type
workshops, Developer roles:
Workshop leader, project leader, scribe, repository manager, construction or SWAT (Skilled With Advanced Tools) team
Rapid Application Development (RAD)
10.9
Methodology: to guide and control the use of RAD techniques Should be automated for ease of use, adaptabilty
and flexibility
Management: Executive sponsor Facilities and support for the RAD team
Rapid Application Development (RAD)
10.10
RAD lifecycle Requirements planning phase (JRP) User design phase (JAD) Construction phase Cutover phase Is evolutionary: Uses timeboxing Avoids “feature creep” Avoids requirements “gold plating”
Rapid Application Development (RAD)
10.11
Rapid Application Development (RAD)
Martin’s (1991) RAD lifecycle Requirements planning phase managers, executives, key users determine requirements in
terms of business areas and business problems, JRP workshops to agree requirements, overall planning
User design phase end users and IS personnel use I-CASE for rapid prototyping
of system design, JAD sessions to develop basis for physical design, users sign off on CASE-based design (no paper-based spec.)
10.12
Martin’s (1991) RAD lifecycle
Construction phase IS personnel now generate code using I-CASE tool, end users validate screens, design, etc.
Cutover phase delivery of new system to users: testing, training,
implementation, can be combined with construction in small systems
Rapid Application Development (RAD)
10.13
Uses timebox approach: system to be developed divided into components that can
be developed separately have the easiest and most important 75% of the system
functionality produced in the first timebox (90 day cycle) forces users to focus on the necessary and most well-
defined aspects Users experience this component first and other
component requirements may then change Functionality is trimmed: “gold plating” is avoided Avoids “feature creep”: more and more requirements creep
in during development than originally specified
Rapid Application Development (RAD)
10.14
Timeboxing vs traditional approach:traditional approach every possible requirement is implemented together leading to increased complexity and long delays
Martin claims RAD can produce a system in 6 months that would take 24 months using traditional development methods
Small development teams are essential for RAD to work
Rapid Application Development (RAD)
10.15
Rapid Application Development (RAD)advantages quick development: cost savings, higher quality/improved performance as easier and most important
functions targeted first, avoids feature creep, aligned with business changes
disadvantages detailed business models/understanding neglected:
inconsistencies,misunderstandings programming standards, scalability, system administration issues
neglected e.g. database maintenance/reorganisation, backup/recovery, distribution of system updates
10.16
Rapid Application Development (RAD)advantages quick development: cost savings, higher quality/improved performance as easier and most important
functions targeted first, avoids feature creep, aligned with business changes
disadvantages detailed business models/understanding neglected:
inconsistencies,misunderstandings programming standards, scalability, system administration issues
neglected e.g. database maintenance/reorganisation, backup/recovery, distribution of system updates
10.17
Application packages
purchasing or leasing a set of pre-written application software programs that are commercially available
may range from simple PC systems to complex mainframe systems
10.18
Choosing application packages: Issues
Cost Functionality Vendor Support Viability of Vendor Flexibility Documentation Response Time Ease of Installation
10.19
Choosing application packages : Process
identify products which may suit specified requirements
solicit, evaluate and rank vendor proposals
select the best vendor proposal establish requirements for integrating
the vendor’s products
10.20
Choosing application packages: Criteria
Identify criteria by which to evaluate hardware and software cost, functionality,vendor support, vendor viability,
quality of documentation, ease of learning, ease of use, ease of installation, response time, throughput, version?, ease of customisation, number of current installations, licensing arrangement, training, internal controls, database size limitation, maintenance contracts, customer references
to help identify criteria you can use past experience, trade magazines and journals,
information services, potential vendors .. bias
10.21
Useful: when you need an information system for a common
company function eg. payroll when information systems resources for in-house
development are in short supply when the application software package is more cost
effective than in-house development because the most of the design and implementation
tasks are done .. significant time saving because the system and documentation are usually
maintained by the vendor
Application packages
10.22
Useful: because the design specification is fixed, so no
endless reworking .. users have to accept it politically because:
external work is often perceived as being superior to an in-house effort .. easier to get new systems into the company
easier to get management support because of fixed costs problems can be attributed to the package rather than
internal sources .. ends endless source of internal conflict
Application packages
10.23
Limitations:
very rare to find a package that can do everything well that a user wants
often need to develop specialised package additions because the multi-purpose packages do not handle certain functions well
conversion and integration costs can sometimes be so significant as to render the project infeasible
some vendors refuse to support packages which have been customised by the users .. and most packages need some customisation
customisation can be so extensive that it would have been cheaper to develop the system in-house
Application packages
10.24
Application packages: ERP Enterprise Resource Planning (ERP) Systems
A large scale application package: a series of software modules for business processes including financial, organisational (e.g. HR), production, inventory functions etce.g. SAP is the market leader
Fully integrated system enabling standardisation and data integrity
Internet and e-commerce technologies Software can be configured for industry
sectors e.g. banking, universities, airlines etc.
(Avison & Fitzgerald 2003, pp 131-132)
10.25
Application packages: ERP
Enterprise Resource Planning (ERP) Systems
Disadvantages: long implementation times, huge investment, impact of widespread change, costs, tendency to change the organisation’s processes to fit the software
Key differences from typical software package purchases:
Complexity causes organisations to forego customisation
Tends to be driven by top corporate managements
(Avison & Fitzgerald 2003, pp 131-132)
10.26
Outsourcing
The practice of turning over some or all of an organisation’s IS applications and/or operations to an outside firm.
Why? May be cost-effective May be specialist in your business area To overcome operating problems Running IS/IT is not part of core business
(core competencies) Need to be aware of the pros and cons
10.27
OutsourcingDiffering definitions of outsourcing e.g. :
The commissioning of a third party (or a number of third parties) to manage a client organisation’s IT assets, people, and/or activities to required results
Fitzgerald & Willcocks (1994) Focus is on the specified service, not on how the
service is to be carried out Growing tendency for organisations to outsource
some or all of their systems development Difficulties in gathering and accurately specifying
requirements in particular Issues and problems in defining and negotiating
contracts and responsibilities Growth of “offshore outsourcing”
10.28
Reuse
reuse of code (software) reuse of analysis and design components reuse of application shells and templates reuse of project management modules
benefits:
- lower costs
- reduction in development time
- increased quality
enterprise-wide planning for reuse is necessary
10.29
Reuse
software reusability:
the ability to design software modules so that they can be used again and again in different systems without significant modification
a repository of reusable components:
- access mechanisms
– modification mechanisms
- integration mechanisms object-oriented technology facilitates reuse CASE tools facilitate reuse
10.30
Reuse
methods of reuse:
- adapt a generic design
- building blocks
- combination
incorporating reuse techniques into SDMs,
e.g. Information Engineering recommends reuse in its later versions