ALARM systems are the most fundamental electronic security solutions. They consist of sensors, zone comms paths, a controller and a communications module, which alerts a remote third party monitoring team to intrusion so it can organise response. It’s all quite straightforward laid out like this. 
But despite appearances there’s plenty to think about from the selection of brand, the performance of controllers, the decision to go with wireless or hardwired zone loops, the choice of sensors and the type of monitoring technology employed. Recent introductions of touch screens, remote apps, video verification and home automation make the decision more complex still. 
When it comes to more complicated ancillaries, the need to ensure you install the best equipment becomes greater still. If you choose to up-sell clients to greater complexity, it must be supported by performance and by reliability or it will become an albatross around your neck. 
Cost and reliability are intertwined – that’s because better systems come at a price. Not a very much higher price, mind you. Fact is, the cost of quality alarm kits is extremely low. It’s obviously possible to spend thousands on an alarm system and turn a suburban house into Fort Knox but there’s always a trade-off between cost and performance – and winning or losing the job. Just be sure to spend a little more on the best systems and components and be astute enough to sell superior technology to users. 
As an installer, the issue when you’re providing alarm systems is ensuring that the technology you install and the way you install it guarantees you will never be called out for a fun half day hunting bugs in a system that’s unsupported in this hemisphere. It sounds a small thing but it’s absolutely vital. 
Reliability is also about customer service and, quite obviously, customer service is what your reputation as an installer is built on. Reliability applies to every aspect of a system, from the sensors to the terminations, from keyfobs to the up-time of the remote comms path to the control room. 
I’ve personally had 4 alarm systems in my life. The most dependable was a DAS NX16. I’ve forgotten what the other systems were now but I do know I stopped using them. One developed a controller fault and would no longer seal. Another ate all its sensor batteries in a month then reported hundreds and hundreds of low battery signals at 50 cents a call while I was on 3 weeks holiday. How I laughed! Another could not resist going into random, raucous alarm for reasons unknown. One day the police came to call and I never armed that alarm system again.  
As a new installer then, choose a quality manufacturer that offers a long warranty on a product that’s tediously reliable. Choose sensors for the application – not whatever costs the least. And again, make the effort to sell your quality selection to users. Be sure users understand that when they ask you to install $20 alarm sensors, they are actually going to get $10 alarm sensors. 
This rule about quality sensors always applies. There’s no point installing slick looking touch screen interfaces in every bedroom that can be accessed from the latest iPad while on safari in the Masai Mara if every afternoon for a 3 month period over winter the lowering sun sparks off the top of that glass table in the family room and blasts a $10 PIR into false alarm. 
This is an area you need to think hard about. Reliability inferred by quality (and sensible installation) means resistance to false alarms. False alarms are the bane of the lives of users. They are the number one reason users give up using their systems and choose to let their monitoring contracts lapse. 
If you are going to install an alarm system, it must be fit for purpose. It’s not there to detect sunbeams, it’s not there to detect cats, flies or thermal currents. It’s not there to detect the UHF conversations of truckies on the freeway. It’s there to detect humans, and only humans. And detecting only humans requires an elevated level of design, build and installation quality not represented by slapped in, mass produced knock-offs trading on volume rather than reputation.
You will definitely ask yourself wired or wireless? It’s a harder choice than it sounds. Sure wireless is easy to install. A child could do it. The trouble is that some wireless is reliable and some is less reliable and some sites are harder than others for RF to get around. Wireless is great if done well but cheap wireless sensors are horrid.  
In comparison, hardwire is expensive once. Hardwire might be tougher to install but it never munches batteries, it never suffers apoplectic fits induced by stray EMI, the nebulous nature of which couldn’t be established by teams of white-coated scientists from the CERN Institute. Let’s be very clear on this. Do your homework on wireless. If you are going to use it, use the best. 

“If you are going to install an alarm system, it must be fit for purpose. It’s not there to detect sunbeams, it’s not there to detect cats, flies or thermal currents.”