42 Professional consultancy based on comparative analysis in the field of design, selection, implementation and use of computer hardware and software systems for others; professional consultancy using analysis of a client's or third party's operation and performance relative to the operations and performances of other entities in the field of design, selection, implementation and use of computer hardware and software systems for others; professional consultancy using comparative analysis of a client's or third party's performance in the field of design, selection, implementation and use of computer hardware and software systems for others; professional consultancy using comparative analysis of a client's or third party's information technology operation in the field of design, selection, implementation and use of computer hardware and software systems for others; professional consultancy using a framework of mathematical models for analysis of a client's or third party's information technology and business processes in the field of design, selection, implementation and use of computer hardware and software systems for others