Custom software development is the designing of software applications for a specific user or group of users within an organization. Such software is designed to address their needs precisely as opposed to the more traditional and widespread off-the-shelf software. Such software is typically created just for that specific entity by a third-party by contract or in-house group of developers and is not packaged for reselling.
Custom software will generally produce the most efficient system as it is can provide support for the specific needs of the business, which might not be available in an off-the-shelf solution and will provide greater efficiency or better customer service.
Given a suitable approach to development, such as DSDM, custom software will also produce the best or most well-targeted service improvement. Businesses can tailor the software to what their customers want instead of having to choose a package that caters for a generic market. For example one printing business may want software that responds in the shortest time, whereas another printing company may focus on producing the best results, as these two objectives often conflict an off-the-shelf package will normally sit somewhere in the middle whereas with custom software each business can focus on their target audience.
Although not always the most suitable for larger or more complex projects, a spreadsheet allows less technical staff at a business to modify the software directly and get results faster. Custom software can be even more flexible than spreadsheets as it is constructed by software professionals that can implement functionality for a wide range of business needs.