Project support: sell watches or results?

Question

Project management

Situation 1: you are a web studio. Handed over and / or accepted for maintenance of the site. Maintenance includes posting content, "finishing" something, solving problems.
Situation 2: you are a client/customer. Found or accepted an offer from a web studio to maintain the site.
What do you need to sell: results or hours of work of a specialist?
1. What are the pros and cons for both parties in the first option (sold/paid to solve a problem or complete a task)?
2. What are the pros and cons for both parties in the second option (sold / paid hours of work of specialists)?
ps How is this done in the "civilized" world?

Answer 1

Project support is a contract with a regulated list of work and a limited number of hours for each of these types of work and response time to each task or failure.
The development / improvement of any new functionality or research is NOT support and is regulated by a separate contract.
The End.

Answer 2

There are people who believe that they paid their pennies and now you owe them all your time. And there are adequate and not hemorrhoids. I usually offer on a subscription fee with a limit, over the limit - a surcharge. Adequate or sign right away or ask for a temporary. A service contract purely for the result often results in slavery. If you want your eye to twitch and your health to go down, you can work for the result.

Answer 3

See how you support.
If you just administer: make sure that it doesn’t fall, set up something little by little, make backups - this is a monthly fee or payment for hours. A list of works included in the subscription service must be attached to the contract.
So you will regularly be with the money, and the customer (in theory) is not afraid that you will deliberately delay the work, because there is nothing to delay.
If you upgrade or change the site (collect and connect new modules to it, change the functionality of the site, redesign design elements, etc.), then these are already mini-projects and you need to pay for them for the result.
The main thing is to discuss the result with the customer and fix the agreement. Well, then - specification, estimate, schedule ... Everything is like in projects, in general.