Using simulation to analyse the impact of software requirement volatility on project performance

Author(s): Pfahl, D., and K. Lebsanft
Venue: Information and Software Technology
Date: November 2000

Type of Experiement: Case Study
Sample Size: 5
Class/Experience Level: Professional


The paper discusses a simulation model developed by Fraunhofer IESE for Siemens Corporate Technology (Siemens CT) to demonstrate the impact of unstable software requirements on project performance. The simulation model also analyzes how much money should be invested in stabilizing software requirements to achieve optimal cost effectiveness. The model was calibrated based on the knowledge of Siemens CT concerning about behavioral patterns of software development projects at Siemens BU (baseline). The paper concludes that based on the simulations, "it was possible to demonstrate that software requirements volatility is extremely effort consuming for the software development organization and that investments in systems engineering in order to stabilize requirements definition would well pay off."

What software or prototypes did the study used? Systems Dynamtics Tool Vensim

An increase of the systems engineering effort share from 1.7% of the total effort (baseline) to 9.1% of the total effort (optimal) will reduce the overall cost for systems engineering and software development by more than 20% (from 596 to 462 weeks). The article mentioned that the results of the model experiments were a twofold advantage:

  1. Deeper understanding of procedures for capturing and changing requirements grew up in the assessment team while discussing about real life and its representation by the model
  2. Quantitative evaluation of the present situation and of the effect of possible changes was convincing for the Siemens business unit