But before you embark on that shiny blockchain project, you need to have a very clear idea of why you are using a blockchain. There are a bunch of conditions that need to be fulfilled. And if they’re not, you should go back to the drawing board. Maybe you can define the project better. Or maybe you can save everyone a load of time and money, because you don’t need a blockchain at all.

Source: Avoiding the pointless blockchain project | MultiChain

Blockchains are a technology for shared databases.
Blockchains are a technology for databases with multiple writers.
blockchains are a technology for databases with multiple non-trusting writers.