PSI - Issue 22

Rosário Oliveira / Procedia Structural Integrity 22 (2019) 151–159 Rosário Oliveira / Structural Integrity Procedia 00 (2019) 000 – 000

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Whenever necessary, a review of the schedule should be promoted, adapting it to the new circumstances. The main objective is to identify gaps and errors in order to implement corrective actions taking into account the return of the delineated time and cost objectives [3]. We know that the more rigorous the control, the greater the probability of acting positively on the events, but the greater the costs associated with the control. As a rule, the control of work deadlines is done through the monitoring of critical activities and eventually those that consume resources with critical availability in doing the work. One of the schedule control techniques is to analyze the yield of resources and to monitor the start and end dates of the activities. In several studies [4, 5, 6] related with the control of deadlines, the main factors responsible for the delays (negative time deviations) were the failures of productivity in the execution phase, the poor estimation of productivity in the planning phase, errors and omissions of design and communication between the various stakeholders in the process. As a norm, cost control is based on budget control, and has the purpose of evaluating the conditioning factors arising from the implementation and to quantify the impact of any decision of the project manager's budget, always with the objective of minimizing these effects. It is argued that cost control of a work should serve to support future budgets of works of identical nature and characteristics. It is based on yields obtained from production that data is obtained for the determination of labor income indices to be used in budgeting; such data also allows the assessment of the economic and commercial risks related to the works. That is, the absence of cost control may lead to: (i) commercial risks, if the contract is awarded not because the price is competitive but because the price is unduly calculated (low price); ii) economic risks, if the cost estimate is deficient, the work may cause loss (loss of value). As stated in [1], monitoring and control time and cost should be carried out from the beginning of the project and based on a realistic and reliable budget, through: a) research technical solutions compatible with the required quality in the execution of the work; b) detection and correction of systematic deviations between the actual and the planned; c) progress reports on the deadline and actual cost, and the estimated deadline and final cost of the work. 3. EVM model in monitoring and control schedule and cost In monitoring and controlling deadlines and costs of a work, sometimes, we question whether their costs are lower than expected because the work is behind schedule so, we do not check the inherent expenses, or if we are spending less than planned. Often, in the assessment of the work carried out on site, we are led to believe that costs are below the expected, when this is because the work that should have been carried out has not yet been completed. So, an indicator that would seem good is in fact, bad. To control these situations, we can use the EVM (Earned Value Management) model that allows an analysis of the performance of the work, based on the integration of scope, deadlines and costs. The EVM differs from the traditional approaches used to control deadlines and costs, since it is based on comparing the expected values with the actual values and expenditures and makes it possible to compare the expected work with the actual work performed and its respective costs. It allows the calculation of the gain value of the work from three data: the planned value of the work, the value of the work performed (value of the work measured) and the value of the actual costs incurred to perform the work. According to [7] the use of EVM makes it possible to obtain warning signals from the initial phase of the work until its conclusion. At any moment it is possible to evaluate the deadlines and costs, check the deviations from the planned, and reformulate the deadlines and costs related to the work that is yet to be completed, in function of the actual performance without harming the completion of the work as initially planned.