The urgency of the problem of planning of the order portfolio of the informatization enterprise (information consulting firm) based on process approach is proved. Moreover, the convergence between project and process approaches in planning of the order portfolio of the information consulting firm is shown. Also the study proposes to use an approach of complex three aspect modeling, consisting of substantial, temporal and cost aspects, according to which each business transaction is assessed as a local cost or profit center, and its start and end time is accounted. Requirements of the order portfolio are formulated and it is proposed to use digitized CASE-models of business processes for planning of the order portfolio of the information consulting firm. The study presents an example of a digitized CASE-model of a generalized business process. These digitized CASE-models are used to get data for the economic and mathematical optimization model that is developed to solve the problem of planning of the portfolio of orders, selected from the totality of possible orders to maximize the net present value of the order portfolio and distribute starting dates of realization of each business-process during the planning period. The model provides the need for interruptions in business-processes. The study proposes software to perform calculations according to the model, in accordance with the assessment of its dimension and also gives an example of calculations.