Learning Objective: At the end of this topic you should be able to: • discuss the implications of selecting, implementing and supporting the installation of custom-written and off-the-shelf solutions;
Application Software • Off-the-shelf • can be purchased, installed & used immediately • written to solve a specific problem, • designed to do one particular task, • e.g. order entry, payroll, stock control, appointments. • Custom-written • tailor-made, bespoke software • designed and written specifically for a company • written especially for them • using a programming language or a DBMS • tested by the developers before installation
Off-the-Shelf Software Advantages of buying an off-the-shelf package: • generally less expensive than custom-written • “economies of scale”, more sold = lower price • readily available • can be bought (shop/Internet) and installed straight away • large, established user-base • advice, forums, 3rd party books, training courses • staff may already be familiar with software • software is tried and tested • fewer bugs than newly written software • software runs on a wide range of hardware • standard file format
Off-the-Shelf Software Disadvantages of buying an off-the-shelf package: • total cost of ownership can be high • annual subscription • upgrades may be expensive • non-specific software • software may not completely fit the task • may have to be customised to completely meet requirements • may have too many additional, unwanted extras • cost of buying functions which are not required • larger memory footprint than custom-written • higher specification computers required?
Custom-written Software Advantages in buying custom-written software: • designed to do exactly what the user wants • end-user owns the software • can sell it on to recoup some of the development cost • can be written to run on user-specified hardware • memory footprint likely to be smaller than off the shelf • can be integrated with existing software
Custom-written Software Disadvantages in buying tailor-made software: • time consuming to have developed • can’t have it now, • expensive • pay for analysis, design, development • only one copy sold • developer may go out of business • limited support • only from developer • nobody else using the software • no 3rd party books available • no training • new staff unlikely to be familiar with software