13.4. Revenue from contracts with customers by type of contract
| NOTE | Refining Segment |
Petrochemical Segment | Energy Segment | Retail Segment |
Upstream Segment | Corporate Functions | Total | ||||||||
| 2021 | 2020 | 2021 | 2020 | 2021 | 2020 | 2021 | 2020 | 2021 | 2020 | 2021 | 2020 | 2021 | 2020 | ||
| Based on fixed price contracts | 55 703 | 33 348 | 11 576 | 8 124 | 15 990 | 10 084 | 40 843 | 30 620 | 797 | 482 | 413 | 61 | 125 322 | 82 719 | |
| Based on variable price contracts | 1 112 | 599 | 4 427 | 2 456 | 14 | 6 | – | – | – | – | 2 | – | 5 555 | 3 061 | |
| Settled on the basis of time spent and materials | 134 | 126 | – | – | 1 | 1 | 2 | 4 | – | – | 5 | 4 | 142 | 135 | |
| 13.1 | 56 949 | 34 073 | 16 003 | 10 580 | 16 005 | 10 091 | 40 845 | 30 624 | 797 | 482 | 420 | 65 | 131 019 | 85 915 | |
In the Group, most contracts with customers in exchange for the goods / services provided are based on a fixed price, and thus the revenues already recognised will not change.
The Group classifies as revenues from contracts based on a variable price, when the consideration is a variable fee on turnover, customers have the rights to trade discounts and bonuses and a part of revenues related to penalties. Revenue from contracts with a variable amount is presented mainly in the Refining, Petrochemical and Energy segments. Contracts accounted for on the basis of time and effort consumed include long-term contracts, among them construction and IT contracts.