Choosing the right contractor has always been a huge problem for owners to decide due to the strong influence of price as tendered by the contractors.
One is to note that there are many ways to get the job done and overseeing the whole installation works has always been a nightmare for site superintendent officers ( SO ) because few are knowledgeable enough to provide good check and balance to ensure that the installed works ( mostly buried ) are professionally carried out to the best interest of the owner i.e. to ensure that the installed system will be totally functional to the life-span of the designed system.
As such, a lot of irrigation works are left to the contractors and one can find numerous jobs that have failed which can be attributed to poor installation other than wrong choice of materials, etc. Examples of poor installation is the lack of knowledge of the required specifications and requirements, poor “priming” and gluing techniques for pipes and fittings, poor wire joints, etc. ( to note that there are numerous pipe joints underground ).
One of the best way to determine the reliability of the contractors is to choose one with a long proven track record and one can always check the credentials and reliability of the contractors from the established golf courses. At times, one also need to thoroughly check out the tenderers’ details of completed works to ensure the correctness of the details. Another way to check and compare the performance of contractors is to contact golf course architects’ construction representatives who have been associated with various irrigation contractors and seek their comments and advices. 
The general understanding in the golf course industry ( for a great number of owners ) is that automatic irrigation system especially those with Centrals is a waste of money and will not work in our country  due to the severity of lightning here other than the lack of knowledge to operate even an Automatic Stand Alone System and not to mention the seemingly high qualifications required to operate the Central Computerise Irrigation System. A contractor that carries ample stocks of spares and being able to provide fast and correct back up services will greatly help in keeping the installed system from failing.
An experienced contractor through experiences shall be able to provide “good” As-Staked plans. The As-Staked plans are the basis for the location of every sprinklers, controllers, routing of mainlines, etc. A not well done As-Staked plan can mean unnecessary addition of sprinklers, non uniform spacing of sprinklers resulting in uneven distribution of water, sprinklers being out of sight from the controllers’ location, etc. 
The right contractor should be able to provide all necessary protections, in the way of good grounding and superior surge protectors, sometimes way above the specifications as recommended by the manufacturers and all the necessary training on the operation of the seemingly difficult automatic irrigation system ( it is not “Rocket Science ) and ensure that the golf course superintendent is confident in the usage of the system which is a very important tool for him or her to maintain the golf course to the highest standard.
Choosing the right contractor can dismiss the fallacy that Automatic Irrigation Systems can only work in highly developed countries. There are a number of such systems here and Singapore that have been operating with limited downtime only. 
One may have a good design and proven products for the golf course but without a good contractor, problems will surface sooner or later.