Lets start by explaining when NOT to use this service. Red-amber.green is intended to monitor BUSINESS STATUS and not INFRASTRUCTURE STATUS.
There are numerous excellent services available for monitoring infrastructure status ("uptime" or "availability") of system components. (We would recommend ohdear.app).
Our service is focussed on usage and business outcomes, so assuming your application is "up and running", your users and stakeholders need to know that desired outcomes are being achieved. For example:
Some more examples of typical use cases, but you can monitor anything you want...
As a team manager of a support system, I need to ensure that enough users are logged in to be available for support requests. Simply add a monitor "Available users" and adjust the status on user logon within your application.
As a sales manager, I need to keep an eye on my sales team daily sales targets. Set up a "Sales Target" monitor and adjust status on each successful sale. This is also a good example of role based monitors, since you can also assign a monitor to each sales agent - so each agent can monitor his/her own sales KPIs, and a higher level team monitor can reflect the team status.
As a stock controller, I need to be aware of current stock levels at all times. Add a "Stock Level" monitor and adjust status on receipt of stock and successfull orders. When stock levels drop below a certain level, move the status to amber to allow for pro-active resolution.