Design and construct of complex civil engineering systems: A new approach to organization and contracts

Presently, the realization process of Complex Civil engineering systems is more and more often arranged with Design & Construct (D&C) contracts. With such a contract both design work as well as construction work are delegated to one single Contractor. For Clients this type of contract is attractive. Dealing with one organization only, no disputed responsibilities and saving money and time due to better constructability of the design are important advantages. The often heard and important disadvantage, namely less control possibility of the realization process, does not seem to be a constraint in the growing popularity of this type of contract for the time being. This does not mean that the present D&C practice could not be an obstacle to definite success of D&C contracts. Purpose of this study: This study is aimed at the development of a control system for D&C of complex civil engineering systems, with organization and type of contract as main components. D&C in theory: The goal of D&C is the search for an effective solution to a problem, which can be - and will be - implemented efficiently. The goal at the start of D&C, however, can hardly be defined as the perceived problem is different from the actual problem and the solution to the problem is, at best, known in a rough conceptual form. In most cases, the badly defined goal makes that the required performance of the conceptual solution at the start of D&C is not sufficient for the effective solution which is needed at the end of D&C. This results in various risks for both Contractor as well as Client. For optimal D&C, it is necessary that the risk should be carried by the party best able to either control or estimate the risk. Hence, "perception risks" are to be carried by the Client who might control the risks with goal adjustment. The “process risks" are to be carried by the Contractor, controlling the risks with the productivity of his D&C process. The underestimation of D&C is hardly distinguished in the present D&C practice. Both Clients as well as Contractors experience D&C as a construction work preceded by some minor design work only (optimization on details). Both parties mistakenly assume that the goal is clearly defined and the efforts can be estimated. D&C is still arranged based on a Fixed-Price contract. Due to the badly defined goal, the underestimation of efforts and the rigid type of contract, however, the D&C Contractor has a control problem. He thought to construct and install the concept, but as it turns out he must first search for an effective solution. Since, in most cases, he has already started with the execution of various components of the concept, the search for an effective solution becomes difficult, enhancing the costs. Although these additional costs originate from the previous project phases combined with the wrong perception of what D&C in fact is and not from the disappointing performance of D&C itself, these costs will not be compensated automatically. Since the cost overruns will normally be claimed, the Client is confronted with the risk of a-possibly large - price overrun and a solution offering more possibilities than was originally called for. This last aspect is caused because there is no contractual room for goal adjustment between times. The requirements for a control system for D&C: The main condition for optimal D&C is that the Client takes and controls the "perception risks", whereas the Contractor takes all "process risks". This is possible in case: (1) the goal is quantified at the start of the contract period (initially required performance of solution), (2) the actually required performance can be measured with respect to initially required performance, (3) the actual performance can be adjusted and (4) the extra efforts needed for actual performance exceeding the initially required performance, can be determined and made reimbursable. Quantification of the required performance: The quantification of the required performance is possible by considering the conceptual solution as a system and decomposing the system into specific part-systems. Those part-systems refer to a number of phase-systems such as, for example, construction, utilization, etc. and to specific aspect-systems of equal scope and significance which are relevant to the distinguished phase-systems. Such aspect-systems are for instance strength and stability. By taking into account the relations between these aspect-systems it is possible, with a simple transformation, to express the required performance into the sum of the required performances of the conceptual solution during the phase-systems. The performance itself is expressed in key-figures for aspect-systems. Measurement of a change in the required performance: By measuring the key-figures of the aspect-systems during D&C, it is possible, using the above transformation, to establish the changes in the required performance with respect to the initially required performance. Possibility of goal adjustment: When confronted with a change in the required performance, the Client can decide on a goal adjustment by selecting a suitable aspect-system, in most cases capacity or maintenance, on which costs can be saved. With the above transformation, the influence of such an adjustment on the overall performance can be determined. Reimbursement of a change in the required performance: Reimbursing changes in the required performance is possible with a new type of contract, the Fixed-Price-Performance-Reimbursement D&C contract (FIPPER D&C). Without taking into account non-quantifiable uncertainties, a fixed price is agreed on for D&C with the conceptual solution as a frame of reference. With a proportionality principle between performance and efforts needed for that performance, a change in the required performance with respect to the initially required performance is made reimbursable. Organization: The organization is aimed at controlling D&C by using aspect-systems. The Client takes over control in case the initially required performance is exceeded or a goal adjustment is desirable. Together with the type of contract as described above, it is possible to fully, dynamically and continuously control D&C. Case studies: The present D&C situation is illustrated with a case study: The Storm Surge Barrier in the Nieuwe Waterweg, Rotterdam. The proposed control system is partially illustrated with three case studies: (1) the Ekofisk Protective Barrier, (2) the Storm Surge Barrier in the Eastern Scheldt and (3) the Storm Surge Barrier in the Nieuwe Waterweg, Rotterdam.