Commercial off-the shelf software, commonly known as COTS, is the type of computer application that can be purchased at any computer retail store or from a software vendor. Examples at the smaller end of the spectrum are most anti-virus programs, games and even computer utilities, such as word processors, database managers, spreadsheet creators and so on. But, COTS such as an big company accounting system or an Enterprise Resource Planning (ERP) package can cost millions, too.

COTS software is usually less expensive than custom created software. This is because many such packages are designed to be used by millions of users worldwide. Since a lot of time and effort has been put into creating such software, creating a COTS application that will only aid a select few number of people would be a waste of money on the part of the developing company. Another point is COTS software is usually very reliable. Developers of COTS components conduct research into the most common types of business processes or problems solving techniques and compress them into software packages that can be used across the board.

It is important to note that any software product that is bought as an “out of the box” product is COTS. Inexpensive examples, like word processing or tax return software are easy to find and purchase from retail stores. Furthermore, these small COTS applications are easy to install, with instructions contained in the package that encloses the COTS product. An electronic copy of the instructions is also usually included on the disc that contains the installation files and resources and in several languages to boot. But for big COTS packages, it’s a different story: one Government agency spent over $750 million and took 10 years to implement their ERP, with lots of customization — and customizing COTS is often very expensive.

Even though companies can make do with freeware or open source software, it is often a requirement on their part to ensure that majority of the applications they rely on are COTS products. This is because, other than having installation instructions, most of the COTS applications have a customer care section that aids any organization that has bought their product. So long as it is legally purchased and registered, usually online, organizations, and even individuals, can obtain help from the company’s customer care representatives, either by telephone or at least online via email or chat. When a problem is discovered with the COTS product, it will be usually taken care of using a patch, or fix. A patch will cover the reported defect(s) that may make the product vulnerable to hackers or operate incorrectly. A “fix”, on the other hand, usually addresses a small issue that gets in the way of normal operation of the product.

When a COTS product is redesigned in any way to meet a specific user’s needs, it is sometimes called a modified off-the shelf (MOTS) product. Unlike COTS software, MOTS is often accompanied with modifiable source code that allows the owner, if they have enough knowledge, to change the product to their choosing. Usually, if a strictly COTS product is modified from the original version, that act “voids” any warranty from the developing organization and so maintenance is left to the user. Any patches or fixes that may not work are no longer the developer organization’s problems.