UNIVERSITY OF HERTFORDSHIRE
		 COMPUTER SCIENCE RESEARCH COLLOQUIUM


           "The Role of Ripple Effect in Software Evolution"


		       	   Dr. Sue Black
                   London South Bank University, UK

		      8 February 2006 (Wednesday)

			  Lecture Theatre E350
		       Hatfield, College Lane Campus
			       3 - 4 pm

	       Coffee/tea and biscuits will be available.
			 [Catering Permitting]

		    Everyone is Welcome to Attend
			  [Space Permitting]


Abstract:

The ripple effect measures source code from two points of view: a)
impact, or how likely it is that a change to a particular module is
going to cause problems in the rest of a program or system; b) the
complexity of a particular module, program or software system. One
specific use of the ripple effect is to measure the complexity of the
first version of a system then use this as a benchmark for comparison
with subsequent releases of the system. If the system becomes more
complex over time (which it probably would be expected to) ripple
effect can be used to highlight where that increase in complexity is
occurring and steps taken to minimise unnecessary complexity. Lehman's
laws of software evolution look at how a system changes over time;
they grew out of the analyses of many releases of the IBM OS 360. Thus
it is evident that there is a link between ripple effect and the laws
of software evolution, as ripple effect can be used to measure the
evolution  of a system in terms of its complexity.

This talk focuses on the link between the ripple effect and Lehman's
laws of software evolution. In particular, it looks at the practical
implications of the laws and discusses using ripple effect via REST
(Ripple Effect and Stability Tool)  to provide useful information for
future software evolution planning and management. As ripple effect is
used during the maintenance  of software systems, several software
maintenance models are described which include accounting for ripple
effect as one of their stages. Recent work on the FEAST project has
highlighted the need for tools to address the practical implications
of the laws of software evolution. Ripple effect as part of a suite of
software measures can be used to address the decline of systems over
time by providing change data that facilitates the optimal modelling
of system trends.

--
Hertfordshire Computer Science Research Colloquium
http://homepages.feis.herts.ac.uk/~nehaniv/colloq