Is a DIY home security system effective?

I’m thinking about going for DIY home security systems. I know I’m not tech-savvy and don’t know anything about my specific needs, the components and the installation process. The main reason I’m going for DIY is that it’s right under my budget. I talked to the best home security system company that I know of, they told me that they will provide you with easy-to-follow instructions for seamless installation.

I know that I would have a hard time following the instructions. However, if I can follow the instructions and install the DIY home security system to protect my home. I want to ask if this DIY home security system really works?