Agri Kultuur February / Februarie 2016

Any change during a project involves an interaction between the following three factors. Cost Quality Time Figure 3. Cost-quality-time triangle For instance, if a certain task’s completion date needed to be brought forward (time), it could only be done by increasing resources (cost) or reducing quality. The time cannot be reduced by keeping costs and quality as they were. The later the changes, the worse the effect on one or more of cost, quality and time. The following looks at the feasibility of changes to the irrigation design during each of these phases. Changes in irrigation design – Definition phase The preliminary irrigation design takes place during this definition phase. Changes are very feasible. This phase is earmarked for changes and this is the phase to get a reasonably clear idea of what one wants. Changes in irrigation design – Planning phase This is the phase where the irrigation design is formulated. Materials will be procured against this design. Changes are still reasonably feasible during the planning phase. Changes in irrigation design – Implementation phase Procurement of materials occurs during this phase. Once procurement has begun, changes are more difficult. Irrigation equipment for instance is often only manufactured-to-order. Construction and installation occurs during this phase. Changes now begin to have a more severe effect with increased costs, time delays or a reduction in quality. This is the phase in irrigation systems where most changes through inadequate planning come to light. Changes in irrigation design – Close-out This is when commissioning takes place and where changes are for all intents and purposes not feasible. The Project Manager and the integration of the irrigation with the rest of the project The irrigation part of the project cannot be viewed in isolation at any time during the project life-cycle. The irrigation involves the interaction of the following aspects and individual specialist personnel, which must be catered for, planned and integrated from the outset. The Project Manager is the key person who must be on the ground from beginning to end to facilitate interaction of the irrigation designer and irrigation contractor with:  Agronomy, including:  Cultural practices  Nutrition  Water source  Land-levelling  Greenhouse design and installation including:  Climate control  Heating  Electrical power supply  Infrastructure, including:  Roads  Buildings

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