A method in a network service manager server to minimize the amount of bandwidth reserved for each network link in a network that includes a plurality of network elements (190, 195) whose bandwidth is being managed by the network service manager server, each of the network links coupling different interfaces on different ones of the network elements (190, 195), the method comprising the steps of: receiving a change to a service family within a set of one more service families, wherein each of the service families includes a set of one or more service versions, the change being to a service version where each of the service versions in the service families comprises one or more network links and comprises a bandwidth requirement representation for each of those links, each of the service versions has a status being one of obsolete and a set of two or more non-obsolete statuses, the non-obsolete statuses include activated, and only one of the service versions in each of the service families can have the status of activated at a time; determining that the change would affect a reserved bandwidth on at least one of the network links affected by the change, wherein the reserved bandwidth for each of the network links is the bandwidth represented by a total of the maximum bandwidth requirement representation for that network link by any non-obsolete service versions within each of the service families wherein at least two of the service versions within at least one of the service families specify different bandwidth requirement representations for the same affected network link and the larger of these bandwidth requirement representations is the maximum bandwidth requirement representation for the service family; and analyzing whether to accept the change based on how the change would affect the reserved bandwidth relative to an available bandwidth on each of the network links affected by the change, wherein the available bandwidth on each of the network links is the reserved bandwidth on that link and any unreserved bandwidth on that link; and changing, on each of the network links whose reserved bandwidth is affected by the change, the reserved bandwidth according to the change if the change is accepted. receiving a change to a service family within a set of one more service families, wherein each of the service families includes a set of one or more service versions, the change being to a service version where each of the service versions in the service families comprises one or more network links and comprises a bandwidth requirement representation for each of those links, each of the service versions has a status being one of obsolete and a set of two or more non-obsolete statuses, the non-obsolete statuses include activated, and only one of the service versions in each of the service families can have the status of activated at a time; determining that the change would affect a reserved bandwidth on at least one of the network links affected by the change, wherein the reserved bandwidth for each of the network links is the bandwidth represented by a total of the maximum bandwidth requirement representation for that network link by any non-obsolete service versions within each of the service families wherein at least two of the service versions within at least one of the service families specify different bandwidth requirement representations for the same affected network link and the larger of these bandwidth requirement representations is the maximum bandwidth requirement representation for the service family; and analyzing whether to accept the change based on how the change would affect the reserved bandwidth relative to an available bandwidth on each of the network links affected by the change, wherein the available bandwidth on each of the network links is the reserved bandwidth on that link and any unreserved bandwidth on that link; and changing, on each of the network links whose reserved bandwidth is affected by the change, the reserved bandwidth according to the change if the change is accepted.