Alternative approaches for acquiring software:

There are some alternative approaches for acquiring software. They are: 

i)  'off the shelf' software package 

ii)  'turnkey' package (both hardware and software) 

iii)  write your own package 

iv)  have customised programs written for you. 

Each of these approaches has its own advantages and disadvantages. Standard packages are by far the most common way of acquiring software. They offer simple and relatively cheap option, with the advantage of a large group of users of common package.

Turnkey systems, with all components of hardware, software and communications provided by the vendor (supplier) are simpler for their users as every aspect is looked after by the supplier. This is a common method pursued by some larger libraries. It is desirable that the package acquired is an integrated one - that is to say it can carry out a number of functions within a common framework. 

Examples could be library automation packages, incorporating acquisitions, cataloguing, circulation etc. There is one possible drawback associated with fully integrated packages, apart from not being flexible; some elements of integrated packages might be inferior to a program dedicated for the same purpose. For example, if database applications are particularly important, it could be a mistake to rely on the database component of a standard package. The 'customised' approaches provide flexibility and a product geared precisely to your specific needs. Though popular, software specially written for information services is too expensive and difficult to maintain and modify for it to be a realistic option in many cases. Some ability to modify software is desirable and standard packages offer the chance to modify such aspects as output formats, and help message. Also, some larger systems are available in modular form, with distinct pieces of software carrying out specific functions. Modules for particular purposes can be acquired and then combined as required, giving a fair degree of flexibility in the look of a software system. The obvious example is the library house keeping package with separate modules for acquisitions, cataloguing, circulation, etc..