Hello fellow IT professional, I suggest you start by putting yourself in your staff's shoes and asking yourself the big question. Am fairly sure the most pressing question in their minds is "Are we going to lose our jobs after this change is completed?". Based on what you have said so far, it doesn't look too good for your present staff as they are not being trained to acquire the skills set needed to carry the new system upon its completion and they are not part of the development process. In fact through their eyes, it seems that all the Company wants from them is information about the old system for input into the development of the new system. It looks to me like self preservation has already kicked in; it is said "It is usual to expect persons to act in their own interest, and unreasonable to expect otherwise". The group theorists say "...persons will stick together to face a common threat....".
Regardless of the answer to the question, you have a need that must be met right now (i.e. for info about the old system to be given to the developer of the new one to make it better in the long run). You could start by drafting up a training schedule and commence training them in PHP and any other skills they may need in the future. Database design remains the same regardless of the software environment in which it is placed and while I am not familiar with Postgresql (I am a MySQL person) I believe that the actual commands should be somewhat similar. In fact they should be able to map each command from MS Access and MSSQL to Postgresql with very little difficulty. They would have already been using about ODBC connectors etc so that should be a plus for them.
Firing may not help as you would end up losing valuable information that is needed for input into the development of the new system. Beyond that though, you need to talk with your staff, let them feel like they are a part of the process. It may be late now but try to get them involved; am hoping that things have not deteriorated to the point where there is a complete lack of trust. Let them know that while everyone cannot be involved at this stage, information is needed from each of them to feed into the development of the new system. Get their input into the design phase as well; you have to sell it to them that they will be required to maintain the new system when completed so it is very important that they commence learning about it from now.
Above all be honest with your staff, if there may be displacements, say so, discuss strategies that may be used to offset displacement e.g retraining and redeployment to other areas. You sound very down yourself. SNAP OUT OF IT VERY QUICKLY!!!!!!!!!!!!!.
Get creative with your staff let them know that upon completion of this project there will be a "New Look" IT department and that you want them ALL to be a part of it. Let them know that one very important requirement for being in the new look department is how well they handle change. Am sure they are all aware that technology is a very dynamic field and part of the whole dynamics is change of the knowledge entity itself. Let them know that as technology changes, the knowledge necessary to manage it must itself be changed from time to time, and that this is one such moment in your company. You must be bursting with motivation and exuding confidence about this project and you must influence your staff to experience it with you. Good luck and CHEERS!!!!
