1. Custom Software v Off-the Shelf Software

2. 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;

3. 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

4. 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

5. 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?

6. 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

7. 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