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. Disadvantages The main disadvantages of custom software are development time and cost. With a spreadsheet or an off-the-shelf software package, a user can get benefits quickly. With custom software, a business needs to go through a Software development process that may take weeks, months, or with bigger projects, years. Bugs accidentally introduced by software developers, and thorough testing to iron out bugs, may impede the process and cause it to take longer than expected. However, spreadsheets and off-the-shelf software packages may also contain bugs, and moreover because they may be deployed at a business without formal testing, these bugs may slip through and cause business-critical errors. Custom software is often several times the cost of the other two options, and will normally include an ongoing maintenance cost. This will often make custom software infeasible for smaller businesses. These higher costs can be insignificant in larger businesses where small efficiency increases can relate to large labour cost savings or where custom software offers a large efficiency boost. Hybrid model Particularly with modern cloud software, a hybrid model of custom software is possible in which the main focus is on the commercial off the shelf software - mainly the mismatch between its features, functions and the business requirements, preferences and expectations. The idea here is to buy a commercial off the shelf software which satisfies maximum number of requirement and develop custom software (extensions or add-ons) to fill the gaps left by it. This is the standard approach used when implementing SAP ERP, for example. See also Bespoke Software development References Computing terminology