You are correct that there is nothing there and makes sense that the function or type of sever is not defined or changes during the lifecycle. In the past I have added a business rule on the cmdb_ci table to look for changes in class and has an asset record to do something like this below:
updateAssetMC();
function updateAssetMC(){
var asset = current.asset;
var newClass = getModelCat(current.sys_class_name);
var gr = new GlideRecord('alm_asset');
gr.addQuery('sys_id',asset);
gr.query();
if(gr.next()){
if(newClass){
gr.model_category = newClass;
gr.update();
}
}
}
function getModelCat(c){
var gr = new GlideRecord('cmdb_model_category');
gr.addQuery('cmdb_ci_class',c);
gr.query();
if(gr.next()){
return gr.sys_id;
}
}
