A system for executing multi-user CAx environments comprising: a host computer including a processor and a memory, the processor and memory configured to operate a multi-user CAx environment; said host computer configured to communicate with a plurality of local computers (104,106,108), each of said local computers including at least one CAx software package and configured to operate a local CAx environment (112a,112b) of said multi-user CAx environment; a feature list stored within the memory of the host computer, the feature list including a list of each feature of a part file, and wherein the feature list is a chronologically ordered list and each feature in the feature list includes a timestamp; and a deletion prevention module stored within at least one of the memory of the host computer and a memory of each of the local computers, the deletion prevention module configured to prevent deletion of a prior feature currently accessed by at least one local CAx environment, wherein the prior feature is a feature accessed in at least one of said local CAx environments and is a feature other than the most current feature, and wherein the deletion prevention module is configured to cause the host computer to poll each local CAx environment and determine a currently active feature in each of said local CAx environments in response to a feature deletion request; the system characterised in that: the deletion prevention module is configured to prompt each local CAx environment accessing the prior feature in response to a feature deletion request, wherein the prompt includes an option for a local user accessing the prior feature to allow the prior feature to be deleted; and wherein the local CAx environment of the local user is configured to cause the at least one local CAx environment currently accessing the prior feature to change from accessing the prior feature to access a feature in the feature list having an earlier timestamp than the prior feature in response to said local user allowing the prior feature to be deleted. a host computer including a processor and a memory, the processor and memory configured to operate a multi-user CAx environment; said host computer configured to communicate with a plurality of local computers (104,106,108), each of said local computers including at least one CAx software package and configured to operate a local CAx environment (112a,112b) of said multi-user CAx environment; a feature list stored within the memory of the host computer, the feature list including a list of each feature of a part file, and wherein the feature list is a chronologically ordered list and each feature in the feature list includes a timestamp; and a deletion prevention module stored within at least one of the memory of the host computer and a memory of each of the local computers, the deletion prevention module configured to prevent deletion of a prior feature currently accessed by at least one local CAx environment, wherein the prior feature is a feature accessed in at least one of said local CAx environments and is a feature other than the most current feature, and wherein the deletion prevention module is configured to cause the host computer to poll each local CAx environment and determine a currently active feature in each of said local CAx environments in response to a feature deletion request; the system characterised in that: the deletion prevention module is configured to prompt each local CAx environment accessing the prior feature in response to a feature deletion request, wherein the prompt includes an option for a local user accessing the prior feature to allow the prior feature to be deleted; and wherein the local CAx environment of the local user is configured to cause the at least one local CAx environment currently accessing the prior feature to change from accessing the prior feature to access a feature in the feature list having an earlier timestamp than the prior feature in response to said local user allowing the prior feature to be deleted. the deletion prevention module is configured to prompt each local CAx environment accessing the prior feature in response to a feature deletion request, wherein the prompt includes an option for a local user accessing the prior feature to allow the prior feature to be deleted; and wherein the local CAx environment of the local user is configured to cause the at least one local CAx environment currently accessing the prior feature to change from accessing the prior feature to access a feature in the feature list having an earlier timestamp than the prior feature in response to said local user allowing the prior feature to be deleted.