In order to value and determine the complexity is taken into account the nature of the contractors (legal entities or determining the ability of their representatives), their nationality, the nature of the contract (administrative, commercial or civil, common or unusual contract) its objective (commercial or industrial establishments, goods, imports or exports goods under special legal regimes, etc..) or special conditions of its contract (mortgages, retro agreements, solar changes for work, security measures, suspension of the effectiveness or resolution, etc.).