[show abstract][hide abstract] ABSTRACT: It is becoming increasingly difficult to predict the resources,
costs, and time scales for the integration of software and systems built
from components supplied by third parties. Many cost models use the
concept of product size as the prime driver for cost estimation but our
experience has shown that the supplied quality of components and the
required quality of the integrated systems are becoming the dominant
factors affecting the costs and time scales of many projects today. ICL
has undertaken an experiment using an alternative life cycle model,
known as the Cellular Manufacturing Process Model (CMPM), which
describes how a product is integrated from its constituent components.
The experiment has helped to develop a method and sets of metrics to
improve cost estimation and project tracking
[show abstract][hide abstract] ABSTRACT: This paper describes a high-level System Dynamics model of a real-world software evolution process. This process is evolving the kernel (low-level routines) of VME, the operating system of a long-lived and successful series of ICL mainframe computers. The model has been developed as part of the continuing FEAST project, which is investigating the role and impact of feedback in the global software process. The modelling approach is top-down, which has resulted in a simple model reflecting elements of the global software process at a high level of abstraction. The actual behaviour of the software evolution process being studied, in terms of enhancements completed and modules added to the kernel over a period of 13 years, is closely simulated by model outputs. The work reported here, together with the previous construction and calibration of an equivalent model for a different type of software product being evolved in a different context, provides support to the FEAST hypothesis, which states that software evolution processes are feedback systems. The models also suggest that feedback pressures from outside immediate technical software processes have an important influence on the dynamics of the overall software process processes, and on the resultant evolutionary product and process trends.
Software Process: Improvement and Practice - SOPR. 01/1999;