The work is designed as an e-learning tool for teaching the construction of patterns for the bra product, intended for post mastectomy women. The functionality of the clothing product is determined by its structure, namely by the textile structure, the design solution, the processing technology. The post-operative functional-adaptive bra, intended for women wearing external breast prostheses, has the role of providing the necessary breast support and fixing the external breast prosthesis in the necessary position. Bras for women wearing external breast prostheses are provided with bra pockets to fix the prosthesis. Functional and ergonomic design of clothing products for people with special needs involves the customization (individualization) of clothing design methods, depending on the wearer's requirements (type of disability, anthropometric peculiarities) as well as the characteristics of the field of use (environmental conditions and body state). All these involve a large amount of work and time. The paper presents a software application for the basic pattern bra product design for women post mastectomy. As initial data for the application there were used: the type of fabric from which the bra is made, anthropometric data on the wearer as well as characteristics of the external breast prosthesis. The application is based on combining knowledge in the field of clothing design with the possibilities of mathematical modelling of the design stages and solving them with the help of computer science theory. The application is an open architecture, which allows its completion and / or modification according to needs. The software application can be used as an e-learning tool in teaching and research activities. As a further direction of development, it is proposed to supplement the application database with the data needed to build the bra model.