Too many variables not in evidence to make an informed response.
Is cctv or guards enough for security of my organization or do I have to adopt a whole security system?
It depends on your choice which type of security you want for your organization' s security. Installing a whole security system gives you overall security includes Cctv and guard security.
Not enough also have to adopt guard security.
Only you can choose. If you wanted to put a security system in your apartment, then you could do something simpler than the whole system. But if you want to put a security guard in your organization, then I think that you should bother a little more. If I were you, I would consider Ajax. I heard a lot of good things about it, then I decided to try it myself and was satisfied. You may think that the prices are a little expensive, but it's worth it. You can see all the info on their website https://ajax.systems/ , there are just the prices. Maybe they won't seem so high to you.
This is the second time I've heard about ajax on the forum and now I'm really interested in finding out what this thing is. I searched the Internet for a little more information on the sub and found that this brand of security system does not produce cctv cameras. However, there is a function that allows you to combine all the available cameras to work in one smartphone application. Such a thing seemed to me quite an interesting solution. Can any of you share with me the experience of using such a mobile application? How convenient is it really?