Information processing system

1 . An information processing system comprising

a processor; and

a memory storing executable instructions that cause the processor to

receive a first input from a user to modify a first hierarchical document and a second hierarchical document that is referred to by at least one document included in the first hierarchical document;

generate a duplicate first hierarchical document of the first hierarchical document and a duplicate second hierarchical document of the second hierarchical document in response to receiving the first input, wherein

the duplicate first hierarchical document includes data corresponding to the first hierarchical document, and

the duplicate second hierarchical document includes data corresponding to the second hierarchical document;

lock the first hierarchical document and the second hierarchical document to prohibit modification of the first hierarchical document and the second hierarchical document;

update reference information indicating reference source information and reference destination information that respectively indicate reference sources and reference destinations in each of the first hierarchical document and the second hierarchical document, the reference information being stored in the memory;

generate document group information indicating that the duplicate first hierarchical document is grouped with the duplicate second hierarchical document based on the reference information;

modify the duplicate first hierarchical document and the duplicate second hierarchical document based on the received input from the user;

update the reference source information and the reference destination information of the reference information in accordance with the modifications made to the duplicate first hierarchical document and the duplicate second hierarchical document;

register modification completed information in the document group information in response to receiving a second input from the user indicating that modification of the duplicate first hierarchical document and the duplicate second hierarchical document is completed; and

unlock the first hierarchical document and the second hierarchical document to overwrite the first hierarchical document and the second hierarchical document with the modified duplicate first hierarchical document and the modified duplicate second hierarchical document.

2 . The information processing system according to claim 1 , wherein the processor is further configured to

in response to receiving the first input from the user to modify a third hierarchical document that is referred to by at least one document included in the first hierarchical document or the second hierarchical document;

generate a duplicate third hierarchical document of the third hierarchical document, the duplicate third hierarchical document including data corresponding to the third hierarchical document;

update the reference information to include the reference source information and the reference destination information that indicates the respective reference sources and the respective reference destinations in each of the first hierarchical document, the second hierarchical document, and the third hierarchical document; and

add the third hierarchical document to the document group information to indicate that the duplicate third hierarchical document is grouped with the duplicate first hierarchical document and the duplicate second hierarchical document, wherein

the reference source information and the reference destination information of the reference information is updated in accordance with the modifications made to the duplicate first hierarchical document, the duplicate second hierarchical document, and the duplicate third hierarchical document,

the modification completed information is registered in the document group information in response to receiving a second input from the user indicating that modification of the duplicate first hierarchical document, the duplicate second hierarchical document, and the duplicate third hierarchical document is completed, and

the first hierarchical document and the second hierarchical document are overwritten with the modified duplicate first hierarchical document, the modified duplicate second hierarchical document, and unlock the modified third hierarchical document.