Pavel V. Malyzhenkov - Professor, Department of Information Systems and Technologies, Faculty of Business Informatics and Applied Mathematics, National Research University Higher School of Economics. 
Address: 25/12, Bolshaya Pecherskaya str., Nizhniy Novgorod, 603155, Russian Federation.
E-mail: pmalyzhenkov@hse.ru

Tatiana S. Babkina - Senior Lecturer, Department of Applied Mathematics and Informatics, Faculty of Business Informatics and Applied Mathematics, National Research University Higher School of Economics. 
Address: 25/12, Bolshaya Pecherskaya str., Nizhniy Novgorod, 603155, Russian Federation.
E-mail: tbabkina@hse.ru

Aleksey I. Sergeev - Post-graduate Student, Department of Information Systems and Technologies, Faculty of Business Informatics and Applied Mathematics, National Research University Higher School of Economics. 
Address: 25/12, Bolshaya Pecherskaya str., Nizhniy Novgorod, 603155, Russian Federation.
E-mail: aisergeev07bi@gmail.com  

      Modern international economic environment is exposed to profound transformations of business operating conditions due to consequences of the financial crisis. Currently the organizational flexibility becomes the most important characteristic of enterprises. In its turn it presumes the adoption of such organizational structures where business relationships and aligned IT infrastructure are recognized as a specific type of the resource that a company can use to achieve competitive advantage. This research analyzes various issues of flexible organization and enterprise models which influence functionality and architecture constraints of enterprise information systems. For the analysis the authors have applied a transactions mechanism concept and specific design methodology. This paper offers an insight into key properties of four flexible organizational forms in tight connection with Enterprise Ontology formal modeling approach and DEMO, which follow the language-action perspective.