Posted at 2017-08-01.
With Individual software you call software, which is custom-made for the solution of a task with a special customer. In contrast to this, one speaks of standard software, if a software is manufactured for a larger quantity of customers, which are often not at all known at the time of the development.
Standard software can be found in nearly unnumbered selections nowadays. This includes functional software (accounting sw, CAD-SW, ...), as well as cross-functional (office packages, ERP, ...) or industry-specific (medical systems, restaurants SW, ...) are now available in almost unlimited selection, , The prices for these systems can range from "free" (e.g., LibreOffice) to "one asset" (e.g., ERP). There are both "open source" and "closed source" or mixed forms of both. In pricing, one should remember, however, that standard software must also be configured, adapted, "updated" and maintained, which often causes not inconsiderable incidental costs.
Often, the decision makers assume that the developers of individual software build the program from scratch - with the C compiler and nothing otherwise. That was once. Today, the developer can access a huge number of building blocks, which are available in source code.
Since the importance of OSS (Open Source Software) is still underestimated in the business sector, we would like to take a look at Wikipedia: 
OSS is therefore not a product of Frickler (tinkerer), in contrast to the frequently expressed opinion, but mostly high-quality software from universities, research facilities, companies and even individuals. A software developer who is familiar with the OSS world and skillfully combines the right components can keep the price of individual software low.
When using standard software you are usually dependent on the manufacturer of this software. Just remember, when introducing a new version of Windows, incompatibilities often occur that require changes in the application software. In this case it is necessary that the manufacturer of the application software responds accordingly - and the update is not too expensive. Similarly, if legal regulations change, business processes are adapted, or ...
With individual software one has usually a maintenance agreement with the software developer anyway. Otherwise you can often access the source code or at least the relevant interfaces so that another company can customize the program. Possibly you can even have the IT department of your company to get to the keyboard.
The use of OSS modules not only shortens the development times, but also the fact that these modules are often already in use, they are tried, tested and low-maintenance. There is often a large community around this OSS, which can help with any problems. In addition to the actual developer, the customer can still access other sources -eventually also for further development and maintenance.
Standardized industry software can not meet the requirements in many companies - if there is one at all. Instead of having to adapt the standard software with a lot of effort and costs, it often takes to start with an individual solution. This is then also tailor-made and efficient.
During operation, it saves costs to reduce the range of functions to the essential. The employees must only be trained in the procedures that are necessary to carry out the task. What does not exist, can not go broken, does not need maintenance, ... This means that the running costs of the software are often significantly lower for individual software than for standard software, which still carries the ballast of all the functions that are not required.
So: You only buy what you need!
And vice versa: What you need, you can also buy!,
because individual software can be expanded, changed, reduced, updated, adapted to your needs at any time ...
The development of individual software makes sense still today, especially when there is no standard software for a specific task or if the adaption of it would need too much effort. The operating costs of standard software could be even higher than those of individual software. Using Open Source Components can make the price of the higher flexibility and user friendliness of tailor-made software competitive.
... because software matters