In addition to the firm from this website:
https://www.edutech-int.com/s_info_system_planning_selection.html I used Charles River
Advisors web site: https://www.charlesriveradvisors.com/ to compare and contrast the services provided by these different firms.
Based on these two different web sites, I need to know exactly how these services provide value to the clients and do these consulting firms use some of the rules of thumb that can be used in information system selection in providing their services?, which ones? (if any), and Why? Can anyone help me with this problem and list references to support your answer.