Alternatives to the Traditional Systems Development Life Cycle

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Alternatives to the Traditional Systems
Development Life Cycle
2
Learning Objectives

• To understand alternatives to the traditional
  systems development life cycle
• To see the advantages and disadvantages of
  developing systems using
• Prototyping
• Application Software Packages
• End-user development
• Outsourcing

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Limitations of the SDLC Approach

• Costly
• A lot of people involved
• Involved for a long time
• Time consuming
• Each step has to be completed before the next
  step can take place as the output of one stage is
  the input for the next stage
• Inflexible
• No scope for short-cuts
• This rigour is necessary for high quality systems.

4
Prototyping

• Involves building an experimental system quickly
  and at low cost for end users to evaluate
• When the end users see the prototype they can see
  if it meets their information needs
• Is a good way to discover the real needs of the
  users, particularly if they find it difficult to
  articulate those needs
• The prototype is then improved so that it more
  closely meets the needs of the users. Each
  iteration gets closer to what is required until
  the final version is satisfactory
• The final version is then converted into the
  final system.

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Advantages of Prototyping

• Prototyping is ideally suited to systems where
  there is uncertainty about the requirements
• By using a mock system the users can become
  clearer about what is important to them
• Particularly the case where the user interface is
  an important issue
• Encourages end-user involvement with the
  development of the system
• More suited to smaller systems with a focused
  scope where the business objectives are well
  defined and narrow.
• Also where the data already exists and the
  project is to report it.

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Disadvantages of Prototyping

• Can lead to poorly technically designed systems
  with poor documentation and inadequate testing
• May not be suitable for large quantities of data
  or many users
• Not suitable where there is a lot of data to be
  created as part of the project
• Not suitable where the technical architecture is
  unclear or where the technology being used is
  relatively new
• Not suitable where there are many people involved
  with the development of the project, particularly
  if they are spread over a large geographical area.

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Application Software Packages

• Packages are common because there are many
  applications which are common to all business
  organisations
• Also industry specific packages have been
  developed to meet the specific needs of
  particular industries, e.g. estate agency to
  manage house sales and lettings
• Packages can vary in size from very small and
  inexpensive to large and more expensive
• Occasionally the packages can be modified, or
  augmented with add-ons to better meet the
  requirements of a particular organisation

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Advantages of Packages

• Leads to a much faster deployment of new systems
• A less risky option as packages should come well
  tested and be reliable
• Vendors will provide the maintenance and support
  as well as initial training
• Can be an existing user base to learn from and
  also find staff with experience of the package
• Should meet most common needs
• Often the only option where there is not the
  resources to create bespoke applications

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Disadvantages of Packages

• Can create a degree of inflexibility and supplier
  dependence
• Particularly a problem if the software supplier
  ceases to trade
• With time the constraints of the package may
  prove to be detrimental to the organisation and
  modification costs may be very high

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End-User Development

• With the advent of more computer literate staff
  some organisations are happy to let the end-users
  themselves develop their own applications
• This is facilitated by fourth and fifth
  generation programming languages such as SQL,
  Access, visual programming tools and object
  oriented programming languages

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Advantages of End-User Development

• Leads to very short development times
• Should enable users to produce exactly what they
  want
• Ultimate in user involvement creating end-user
  ownership of the system
• No need for expensive IS specialists

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Disadvantages of End-User Development

• Limited capabilities of systems developed this
  way
• Slow to process transactions
• Not suitable for a lot of transactions
• Not suited to applications with a lot of
  procedural logic and updating of files
• Risky as no formal control procedures
• Danger of poor documentation and testing
• Can lead to duplication of effort
• Can lead to hoarding of information as opposed to
  the preferred sharing of information
• Can detract staff from their main duties

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Outsourcing

• When firms dont want to build or operate
  information systems in house they can outsource
  it to a specialist company
• The provider benefits from economies of scale and
  has suitably qualified staff
• The provider should also be better able to keep
  up with changes in technology
• The company can have IS provision as a more
  variable cost as opposed to a fixed cost

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Disadvantages of Outsourcing

• There is a potential danger of losing control of
  IS function with outsourcing
• Lack of expertise can lead to a poor contract
  being negotiated with the outside company
• resulting in high costs
• loss of control over technical direction
• Could be secrecy problems

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When Outsourcing is Advantageous

• To reduce costs or offload some of the IS
  departments work
• routine applications
• When existing IS capabilities are limited,
  ineffective or technically inferior
• To improve the contribution of IT to business
  performance
• critical or innovative business applications
• To create new sources of revenue and profit from
  technology assets