International Journal of Differential Equations and Applications Volume 18, No. 1 (2019), pages: 87-98 ISSN (Print): 1311-2872; ISSN (Online): 1314-6084; url: https://www.ijdea.eu P A ijpam.eu A NOTE ON THE EXTENDED SONG–CHANG–PHAM’S SOFTWARE RELIABILITY MODEL. II. Nikolay Pavlov 1 , Georgi Spasov 2 , Martin Stieger 3 , Angel Golev 4 , 1,2,4 Faculty of Mathematics and Informatics University of Plovdiv Paisii Hilendarski 24, Tzar Asen Str., 4000 Plovdiv, BULGARIA 3 Allensbach University Lohnerhofstrasse 2, D-78467 Konstanz, GERMANY ABSTRACT: The determination of compulsory in area of the Software Reliability Theory components, such as confidence intervals and confidence bounds, should also be accompanied by a serious analysis of the value of the best Hausdorff approximation - the subject of study in the present paper. For example we study the Hausdorff approximation of the shifted Heaviside function h t 0 (t) by cumulative function based on the extended Song–Chang–Pham’s model [1] (see, also [2]). We propose a software module within the programming environment CAS Mathe- matica for the analysis of the considered family of functions. We give real example with dataset using the new extended Song–Chang–Pham’s software reliability model. AMS Subject Classification: 41A46 Key Words: four parameters extended Song–Chang–Pham’s cumulative function (4SHPcdf), Heaviside step–function h t 0 (t), Hausdorff distance, upper and lower bounds Received: May 22, 2019 Revised: August 27, 2019 Published: September 11, 2019 doi: 10.12732/ijdea.v18i1.8 Academic Publications, Ltd. https://acadpubl.eu