{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:32:16Z","timestamp":1760146336250,"version":"build-2065373602"},"reference-count":48,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2024,10,29]],"date-time":"2024-10-29T00:00:00Z","timestamp":1730160000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u201cFondo di Ricerca d\u2019Ateneo\u201d of the Univerist\u00e0 degli Studi dell\u2019Insubria"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Software"],"abstract":"<jats:p>Functional size measures are widely used for estimating software development effort. After the introduction of Function Points, a few \u201csimplified\u201d measures have been proposed, aiming to make measurement simpler and applicable when fully detailed software specifications are not yet available. However, some practitioners believe that, when considering \u201ccomplex\u201d projects, traditional Function Point measures support more accurate estimates than simpler functional size measures, which do not account for greater-than-average complexity. In this paper, we aim to produce evidence that confirms or disproves such a belief via an empirical study that separately analyzes projects that involved developments from scratch and extensions and modifications of existing software. Our analysis shows that there is no evidence that traditional Function Points are generally better at estimating more complex projects than simpler measures, although some differences appear in specific conditions. Another result of this study is that functional size metrics\u2014both traditional and simplified\u2014do not seem to effectively account for software complexity, as estimation accuracy decreases with increasing complexity, regardless of the functional size metric used. To improve effort estimation, researchers should look for a way of measuring software complexity that can be used in effort models together with (traditional or simplified) functional size measures.<\/jats:p>","DOI":"10.3390\/software3040022","type":"journal-article","created":{"date-parts":[[2024,10,29]],"date-time":"2024-10-29T08:42:09Z","timestamp":1730191329000},"page":"442-472","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Software Development and Maintenance Effort Estimation Using Function Points and Simpler Functional Measures"],"prefix":"10.3390","volume":"3","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5226-4337","authenticated-orcid":false,"given":"Luigi","family":"Lavazza","sequence":"first","affiliation":[{"name":"Department of Theoretical and Applied Sciences, Universit\u00e0 degli Studi dell\u2019Insubria, 21100 Varese, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6740-8620","authenticated-orcid":false,"given":"Angela","family":"Locoro","sequence":"additional","affiliation":[{"name":"Department of Economics and Management, Universit\u00e0 degli Studi di Brescia, 25121 Brescia, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1069-8548","authenticated-orcid":false,"given":"Roberto","family":"Meli","sequence":"additional","affiliation":[{"name":"Data Processing Organization Srl, 00155 Roma, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,29]]},"reference":[{"key":"ref_1","unstructured":"Albrecht, A.J. (1979, January 14\u201317). Measuring application development productivity. Proceedings of the Joint SHARE\/GUIDE\/IBM Application Development Symposium, Monterey, CA, USA."},{"key":"ref_2","unstructured":"International Function Point Users Group (IFPUG) (2022). Simple Function Point (SFP) Counting Practices Manual Release v2.1, International Function Point Users Group (IFPUG)."},{"key":"ref_3","unstructured":"Meli, R. (2011, January 9\u201310). Simple function point: A new functional size measurement method fully compliant with IFPUG 4. x. Proceedings of the Software Measurement European Forum, Rome, Italy."},{"key":"ref_4","unstructured":"(2003). Software Engineering \u201cIFPUG 4.1 Unadjusted Functional Size Measurement Method\u201d Counting Practices Manual (Standard No. ISO\/IEC 20926: 2003)."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Lavazza, L., and Meli, R. (2014, January 6\u20138). An evaluation of simple function point as a replacement of IFPUG function point. Proceedings of the 2014 Joint Conference of the International Workshop on Software Measurement and the International Conference on Software Process and Product Measurement (IWSM-MENSURA), Rotterdam, The Netherlands.","DOI":"10.1109\/IWSM.Mensura.2014.28"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Lavazza, L., Liu, G., and Meli, R. (2020, January 5\u20137). Using Extremely Simplified Functional Size Measures for Effort Estimation: An Empirical Study. Proceedings of the 14th ACM\/IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM), Bari, Italy.","DOI":"10.1145\/3382494.3410691"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"142505","DOI":"10.1109\/ACCESS.2024.3471428","article-title":"Using Machine Learning and Simplified Functional Measures to Estimate Software Development Effort","volume":"12","author":"Lavazza","year":"2024","journal-title":"IEEE Access"},{"key":"ref_8","unstructured":"International Software Benchmarking Standards Group (2019). Worldwide Software Development: The Benchmark, International Software Benchmarking Standards Group. Release April 2019."},{"key":"ref_9","unstructured":"Lavazza, L., Locoro, A., and Meli, R. (2023, January 14\u201315). Software development effort estimation using function points and simpler functional measures: A comparison. Proceedings of the 2023 Joint Conference of the International Workshop on Software Measurement and the International Conference on Software Process and Product Measurement (IWSM-MENSURA), Rome, Italy."},{"key":"ref_10","first-page":"26","article-title":"Inside SEER-SEM","volume":"18","author":"Fischman","year":"2005","journal-title":"CrossTalk"},{"key":"ref_11","unstructured":"Hacaloglu, T., and Demir\u00f6rs, O. (2018, January 19\u201320). Challenges of Using Software Size in Agile Software Development: A Systematic Literature Review. Proceedings of the IWSM-Mensura, Beijing, China."},{"key":"ref_12","unstructured":"International Function Point Users Group (IFPUG) (2010). Function Point Counting Practices Manual, Release 4.3.1, International Function Point Users Group (IFPUG)."},{"key":"ref_13","first-page":"107","article-title":"On the Effort Required by Function Point Measurement Phases","volume":"10","author":"Lavazza","year":"2017","journal-title":"Int. J. Adv. Softw."},{"key":"ref_14","unstructured":"(2012). Information Technology-Software Measurement-Functional Size Measurement (Standard No. ISO\/IEC 14143)."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/j.jss.2015.11.040","article-title":"The usage of ISBSG data fields in software effort estimation: A systematic mapping study","volume":"113","author":"Lokan","year":"2016","journal-title":"J. Syst. Softw."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1109\/MC.1987.1663694","article-title":"Improving software productivity","volume":"20","author":"Boehm","year":"1987","journal-title":"Computer"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"820","DOI":"10.1016\/j.infsof.2011.12.008","article-title":"Evaluating prediction systems in software project estimation","volume":"54","author":"Shepperd","year":"2012","journal-title":"Inf. Softw. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1109\/MS.1997.582972","article-title":"Counterpoint: The problem with function points","volume":"14","author":"Kitchenham","year":"1997","journal-title":"IEEE Softw."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Fenton, N., and Bieman, J. (2014). Software Metrics: A Rigorous and Practical Approach, CRC Press.","DOI":"10.1201\/b17461"},{"key":"ref_20","unstructured":"COSMIC (2024, October 25). COSMIC Measurement Manual for ISO 19761, Version 5.0. Available online: https:\/\/cosmic-sizing.org\/measurement-manual\/."},{"key":"ref_21","unstructured":"van Heeringen, H., van Gorp, E., and Prins, T. (2009, January 27\u201328). Functional size measurement-Accuracy versus costs\u2013Is it really worth it?. Proceedings of the Software Measurement European Forum (SMEF 2009), Rome, Italy."},{"key":"ref_22","unstructured":"Timp, A. (2015). uTip\u2013Early Function Point Analysis and Consistent Cost Estimating. uTip # 03, IFPUG. (Version # 1.0 2015\/07\/01)."},{"key":"ref_23","first-page":"182","article-title":"A Large-scale Empirical Evaluation of Function Points Estimation Methods","volume":"13","author":"Lavazza","year":"2020","journal-title":"Int. J. Adv. Softw."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1016\/S0950-5849(98)00074-3","article-title":"Construction of an FPA-type metric for early lifecycle estimation","volume":"40","author":"Horgan","year":"1998","journal-title":"Inf. Softw. Technol."},{"key":"ref_25","first-page":"6","article-title":"Function point estimation methods: A comparative overview","volume":"Volume 99","author":"Meli","year":"1999","journal-title":"Proceedings of the FESMA"},{"key":"ref_26","unstructured":"NESMA\u2013the Netherlands Software Metrics Association (2004). Definitions and Counting Guidelines for the Application of Function Point Analysis. NESMA Functional Size Measurement Method Compliant to ISO\/IEC 24570 Version 2.1, NESMA\u2013the Netherlands Software Metrics Association."},{"key":"ref_27","unstructured":"(2005). Software Engineering\u2013NESMA Functional Size Measurement Method Version 2.1\u2014Definitions and Counting Guidelines for the Application of Function Point Analysis (Standard No. ISO\/IEC 24570:2005)."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Bernstein, L., and Yuhas, C.M. (2005). Trustworthy Systems Through Quantitative Software Engineering, John Wiley & Sons.","DOI":"10.1002\/0471750336"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Santillo, L., Conte, M., and Meli, R. (2005, January 19\u201322). Early & Quick Function Point: Sizing more with less. Proceedings of the 11th IEEE International Software Metrics Symposium (METRICS\u201905), Como, Italy.","DOI":"10.1109\/METRICS.2005.33"},{"key":"ref_30","unstructured":"Iorio, T., Meli, R., and Perna, F. (2007, January 9\u201311). Early & Quick Function Points\u00ae v3. 0: Enhancements for a Publicly Available Method. Proceedings of the Proceedings Software Measurement European Forum (SMEF), Rome, Italy."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/3582575","article-title":"Estimating software functional size via machine learning","volume":"32","author":"Lavazza","year":"2023","journal-title":"ACM Trans. Softw. Eng. Methodol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1236","DOI":"10.1016\/j.infsof.2011.05.008","article-title":"The value of software sizing","volume":"53","author":"Wilkie","year":"2011","journal-title":"Inf. Softw. Technol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"455","DOI":"10.2298\/CSIS110316068P","article-title":"A comparative evaluation of effort estimation methods in the software life cycle","volume":"9","year":"2012","journal-title":"Comput. Sci. Inf. Syst."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1007\/s11219-013-9215-1","article-title":"Function point analysis using NESMA: Simplifying the sizing without simplifying the size","volume":"22","author":"Morrow","year":"2014","journal-title":"Softw. Qual. J."},{"key":"ref_35","unstructured":"Lavazza, L., and Liu, G. (2019, January 24\u201328). An Empirical Evaluation of the Accuracy of NESMA Function Points Estimates. Proceedings of the 14th International Conference on Software Engineering Advances (ICSEA 2019), Valencia, Spain."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"106308","DOI":"10.1016\/j.infsof.2020.106308","article-title":"Assessing the effectiveness of approximate functional sizing approaches for effort estimation","volume":"123","author":"Ferrucci","year":"2020","journal-title":"Inf. Softw. Technol."},{"key":"ref_37","first-page":"1","article-title":"An Empirical Evaluation of Simplified Function Point Measurement Processes","volume":"6","author":"Lavazza","year":"2013","journal-title":"J. Adv. Softw."},{"key":"ref_38","unstructured":"Meli, R. (2015, January 19\u201323). Early & Quick Function Point Method-An empirical validation experiment. Proceedings of the International Conference on Advances and Trends in Software Engineering, Barcelona, Spain."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Ferrucci, F., Gravino, C., and Lavazza, L. (2016, January 4\u20138). Simple function points for effort estimation: A further assessment. Proceedings of the 31st Annual ACM Symposium on Applied Computing, Pisa, Italy.","DOI":"10.1145\/2851613.2851779"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/0164-1212(92)90101-O","article-title":"FP-S: A simplified function point counting method","volume":"18","author":"Bock","year":"1992","journal-title":"J. Syst. Softw."},{"key":"ref_41","unstructured":"DPO (2012). Early & Quick Function Points Reference Manual\u2013IFPUG Version, DPO. Technical Report EQ&FP-IFPUG-31-RM-11-EN-P."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1796","DOI":"10.1016\/j.infsof.2013.04.003","article-title":"Towards a simplified definition of Function Points","volume":"55","author":"Lavazza","year":"2013","journal-title":"Inf. Softw. Technol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Han, D., Gu, X., Zheng, C., and Li, G. (2022). Research on Structured Extraction Method for Function Points Based on Event Extraction. Electronics, 11.","DOI":"10.3390\/electronics11193117"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"107088","DOI":"10.1016\/j.infsof.2022.107088","article-title":"An optimized case-based software project effort estimation using genetic algorithm","volume":"153","author":"Hameed","year":"2023","journal-title":"Inf. Softw. Technol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"103329","DOI":"10.1016\/j.advengsoft.2022.103329","article-title":"Prediction based cost estimation technique in agile development","volume":"175","author":"Butt","year":"2023","journal-title":"Adv. Eng. Softw."},{"key":"ref_46","unstructured":"Ugalde, F., Quesada-L\u00f3pez, C., Mart\u00ednez, A., and Jenkins, M. (2020, January 6\u20139). A comparative study on measuring software functional size to support effort estimation in agile. Proceedings of the CIbSE, Online."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Hai, V.V., Nhung, H.L.T.K., Prokopova, Z., Silhavy, R., and Silhavy, P. (2022). A New Approach to Calibrating Functional Complexity Weight in Software Development Effort Estimation. Computers, 11.","DOI":"10.3390\/computers11020015"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1007\/978-3-030-77442-4_45","article-title":"An approach to adjust effort estimation of function point analysis","volume":"230","author":"Ho","year":"2021","journal-title":"Lect. Notes Netw. Syst."}],"container-title":["Software"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2674-113X\/3\/4\/22\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:22:44Z","timestamp":1760113364000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2674-113X\/3\/4\/22"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,29]]},"references-count":48,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["software3040022"],"URL":"https:\/\/doi.org\/10.3390\/software3040022","relation":{},"ISSN":["2674-113X"],"issn-type":[{"type":"electronic","value":"2674-113X"}],"subject":[],"published":{"date-parts":[[2024,10,29]]}}}