Measureability of functional size in Agile software projects: Multiple case studies with COSMIC FSM

Hacaloglu, Tuna
Demirörs, Onur
Functional size measurement (FSM) has been used in software engineering for decades as a main driver for estimation and significant input for other various project management activities throughout the project life span. To apply FSM accurately at the early stages of software development process, especially for estimation purposes, functional user requirements need to be available in detail as required by the adopted FSM method. However, in agile software development, requirement specifications, in general, are kept minimal. For this reason, the adjustment of the requirements to the necessary granularity level has been articulated as one of the barriers preventing the diffusion of FSM practices among agile teams. In this paper, we take a closer look at this problem in order to investigate the usability of FSM and to reveal FSM related challenges empirically through case studies on real agile projects from different software organizations. This study also provides a snapshot of agile organizations in terms of requirement specification and estimation related practices


Reliability of COSMIC Functional Size Measurement Results: A Multiple Case Study on Industry Cases
Top, Ozden Ozcan; Demirörs, Onur; Ozkan, Baris (2009-08-29)
Accuracy of the functional size is critical in software project management, since functional size is the most prevalent input for effort and cost estimation models. Functional size measurement is performed based on standardized manuals; however, the accuracy of FSM results is still based on the knowledge and cautions of the measurers. In this study we performed a multiple case study to identify the reliability of COSMIC and to observe the frequently encountered errors during functional size measurement. Pro...
Exploration of an Error Prevention Model for COSMIC Functional Size Measurement Method
Salmanoğlu, Murat; Demirörs, Onur (2012-10-19)
The reliability of Functional size is crucial for effort and cost estimation in software development projects. However, estimation results may differ because of the errors made in the measurement process. This research proposes an error prevention model for COSMIC Functional Size Measurement method to increase the reliability of the measurements. The model has two main suggestions; first, to use the types of the functional processes during the measurement to prevent errors, and the second, to use a cardinal...
Hacaloğlu, Tuna; Betin Can, Aysu; Demirörs, Onur; Department of Information Systems (2021-9-10)
Software Size Measurement is a critical task in Software Development Life Cycle (SDLC). It is the primary input for effort estimation models and an important measure for project control and process improvement. There exist various size measurement methods whose successes have already been proven for traditional software architectures and application domains. Functional size measurement (FSM) being one of them attracts specific attention due to its applicability at the early phases of SDLC. Although FSM meth...
Evaluation of the Effect of Functional Similarities on Development Effort
Top, Ozden Ozcan; Tunalilar, Seckin; Demirörs, Onur (2008-09-05)
Although functional size is the primary input for effort and cost estimation formulas, the relation between functional size and development effort does not always hold in practice. Calculating the magnitude of functional similarity is perceived as a partial solution to overcome this problem. In this study we applied different approaches to identify the magnitude of functional similarity in five projects. The applicability of these approaches is evaluated by observing the impact of functional similarity on e...
On the Seven Misconceptions about Functional Size Measurement
ÖZKAN, BARIŞ; Demirörs, Onur (2016-10-07)
Among the various approaches to software size measurement, Functional Size Measurement has been widely recognized for its usability in early phases of software development cycles and its independence from implementation language, development method and technology. Starting from its introduction with the original Function Point Analysis method in 1979, functional size has been a favored input to estimation and productivity models. As a result of the search for solutions to emerging measurement needs and the ...
Citation Formats
T. Hacaloglu and O. Demirörs, “Measureability of functional size in Agile software projects: Multiple case studies with COSMIC FSM,” 2019, p. 204, Accessed: 00, 2020. [Online]. Available: