A RUP ‘hump’ is a plot of effort spent over time during a particular Rational Unified Process (RUP) discipline. The RUP hump chart consists of a collection of humps for all RUP disciplines. This diagram was created in 1993 during a workshop on architecture and process  and was inspired by work by Grady Booch  and Boehm. It has been part of the Rational Objectory Process after reviews by Dyrhage and Bylund and moved on to play a more important role in the RUP in 1998 when it served as the initial page for using the digital version of the process. Its final form was published by Philippe Kruchten in 1998. An older version as later used by Jacobson, Booch and Rumbaugh  and an altered version was used by Royce.
Over the years, this diagram has become increasingly connected with RUP, so that sometimes it is regarded as a logo for the process. The chart has then since been spread widely over the Internet. A known misconception about the hump chart is, that it is based on empirical assessment of actual projects rather than on Kruchten's educated guess.
...I always insisted that these humps were just illustrative, as well as the number and duration of iterations shown on the horizontal axis, but many people wanted to read much more meaning in that diagram than I intended. For example, a gentleman from Korea once wrote me to ask for a large original diagram to measure the heights, and ‘integrate' the area under the humps, to help him do project estimation...
Recently Werner Heijstek and Michel R.V. Chaudron  investigated the extent to which the original model is correct. Their findings include data from industrial software engineering projects.
- P. Kruchten. A brief history of the RUP’s “hump chart”. Technical report, University of British Columbia, 2003.
- G. Booch. Object solutions: managing the object-oriented project. Addison Wesley Longman Publishing Co., Inc., Redwood City, CA, USA, 1995.
- B. Boehm. A spiral model of software development and enhancement. SIGSOFT Softw. Eng. Notes, 11(4):14–24, 1986.
- B. W. Boehm. A spiral model of software development and enhancement. Computer, 21(5):61–72, 1988.
- P. Kruchten. The Rational Unified Process: An Introduction. Addison-Wesley Longman Publishing Co., Inc., Boston, MA, USA, 2003.
- I. Jacobson, G. Booch, and J. Rumbaugh. The unified software development process. Addison-Wesley Longman Publishing Co., Inc., Boston, MA, USA, 1999.
- W. Royce. Software project management: a unified framework. Addison-Wesley Longman Publishing Co., Inc., Boston, MA, USA, 1998.
- W. Heijstek and Michel R. V. Chaudron (2008) Evaluating RUP Software Development Processes Through Visualization of Effort Distribution, 34th Euromicro Conference on Software Engineering and Advanced Applications (SEAA 2008) Parma, Italy