A function simulation program, for use by a customer, to be installed on an information processing apparatus such as to configure the information processing apparatus to simulate one, or more than one, function of an image processing apparatus, wherein the simulation program comprises: an actual process library (111, 121, 131, 141, 151) configured to cause the information processing apparatus to simulate one, or more than one, function of the image processing apparatus, by making the information processing apparatus execute processing as if it were just like the image processing apparatus, according to a command from an application program that is installed on the information processing apparatus to make the image processing apparatus execute processing; a virtual process library (112, 122, 132, 142, 152) configured to cause the information processing apparatus to simulate a function corresponding to one, or more than one, function of the image processing apparatus, by making the information processing apparatus execute alternate processing that is more limited than the processing executed by the image processing apparatus when made to execute processing by the actual processing library, according to a command from the application program, the function simulation program further being configured to execute selecting either or both of the actual process library and the virtual process library for every function of the image processing apparatus, as suitable for the customer, and installing the selected library on the information processing apparatus; and a use range table, and another use range table created for the customer based on the first-mentioned use range table, in the information processing apparatus when the simulation program is installed on the information processing apparatus, for one of the plurality of groups, which groups relate to the reliability of customers, which other use range table defines the use range of the actual process library for that group, the program making the information processing apparatus execute judging, based on the other use range table, whether or not a target actual process library is permitted to be used, at the time of activation after installation and activating the target actual process library if it is judged that the target actual process library is permitted to be used or activating a suitable virtual process library if it is judged that the target actual process library is not permitted to be used. an actual process library (111, 121, 131, 141, 151) configured to cause the information processing apparatus to simulate one, or more than one, function of the image processing apparatus, by making the information processing apparatus execute processing as if it were just like the image processing apparatus, according to a command from an application program that is installed on the information processing apparatus to make the image processing apparatus execute processing; a virtual process library (112, 122, 132, 142, 152) configured to cause the information processing apparatus to simulate a function corresponding to one, or more than one, function of the image processing apparatus, by making the information processing apparatus execute alternate processing that is more limited than the processing executed by the image processing apparatus when made to execute processing by the actual processing library, according to a command from the application program, the function simulation program further being configured to execute selecting either or both of the actual process library and the virtual process library for every function of the image processing apparatus, as suitable for the customer, and installing the selected library on the information processing apparatus; and a use range table, and another use range table created for the customer based on the first-mentioned use range table, in the information processing apparatus when the simulation program is installed on the information processing apparatus, for one of the plurality of groups, which groups relate to the reliability of customers, which other use range table defines the use range of the actual process library for that group, the program making the information processing apparatus execute judging, based on the other use range table, whether or not a target actual process library is permitted to be used, at the time of activation after installation and activating the target actual process library if it is judged that the target actual process library is permitted to be used or activating a suitable virtual process library if it is judged that the target actual process library is not permitted to be used.