Whether by need or as a ploy to make takeovers more difficult, manufacturers are and do have the ability to make more secure their future with current customers. For example, Lenel has been deploying their new NGP panels to, it seems, as many of their large installations as possible. These are Mercury Gen 1 code based, but are purely and, reportedly, forever proprietary. Sometimes it is a good idea to have the flexibility to add an HID POE reader to key places in an otherwise Mercury baseline system, or to similarly add wireless lock sets to otherwise difficult or costly to reach areas.
What I feel is that, in the end, standards will be best for the customers, but in the meantime, while looking out for the customer’s future is appropriate, panel purity does not need to be absolute. Takeovers of Mercury and HID panels will usually involve a cost to flash each panel’s OEM specific firmware with the new vendor’s OEM specific firmware, so it will usually not be a cost free swap, even to keep the same panels. So, I like it as a rule, but not an absolute. As discussed earlier, there may be other third party integrations that do not natively transfer (video, visitor management, perimeter, IDS, HR databases, custom reports, custom features,…).
You may also consider, depending on the facility types you have, integrating the burglar alarm & fire (secondary reporting, of course), such as Lenel is doing with their proprietary NGP (burg only) panels, Honeywell does with their Vista panels and others are doing with DMP (much more flexibly than even the native Honeywell integration, I have experienced). Or, if an outside central station is not needed, you can use the Mercury keypads for off-hours burg type security, reporting back to the user-monitored server. In either case, it affords you much more flexibility and control over your security processes.
OK. Two more pet features that could save your customer some grief.
So, if you are securing a multi-facility complex or multi-location monitored organization, you might need to be sure the system has alarm vectoring, so only the regionally pertinent and tailored info is sent to local workstations, preventing inundation are the head end with every minor goings on. Further you may need an automatic escalation of that event to the head-end, or alternate location, should the primary responding location fail to do so in time. Finally, partitioning the database goes hand-in-hand with multi-tenant and multi-site facilities, for both operator convenience and privacy concerns.