Multi-objective planning models for cyclical refurbishment work

CANDU型反应堆有480个Calandria管、燃料通道和进出料器，必须以循环的方式重复更换再管和进料器的过程，这对建设项目调度和资源分配的传统概念提出了挑战。独特的限制条件比比皆是，比如辐射剂量限制、允许同时进入金库的人数以及时间表里程碑。因此，这项研究的主要目标是开发一种工具，以找到许多可能的解决方案中的最佳解决方案，其中包括：(1)相关约束，(2)估计工艺生产率、机器速度和工艺时间变化等参数，(3)多个相互冲突的目标，如生产率、成本、进度、剂量和可预测性，以及(4)登记风险。这一工具的验证将通过使用已经建造的全尺寸模型和培训设施进行的实验来实现。这是一个独特的科学验证机会。这项研究的结果将对整个建筑业产生广泛的影响。我们的合作伙伴将通过利用这一工具和与之相关的新知识来赢得世界各地的类似项目，从而受益。归根结底，所获得的知识也应该适用于加拿大日益增长的预制、模块化和造船业。

With 480 calandria tubes, fuel channels, and inlet and outlet feeders, the re-tube and feeder replacement processes for CANDU type reactors must be repeated in a cyclical fashion that challenges conventional concepts of construction project scheduling and resource allocation. Unique constraints abound such as radiation dosage limits, number of people allowed simultaneously in the vault, and schedule milestones. The primary objective of this research is thus to develop a tool to find the best of many possible solutions to scheduling and resource allocation for nuclear re-tube and feeder replacement type projects that will incorporate: (1) relevant constraints, (2) parameters like estimated craft productivity, machine rates, and variation in process times, (3) multiple conflicting objectives such as productivity, cost, schedule, dosage, and predictability, and (4) registered risks. Validation of this tool will be enabled by experiments conducted using the full-scale mock-up and training facility already constructed. This is a unique opportunity for scientific validation. Results of this study will have broad impact across the construction industry. Our partners will benefit by leveraging this tool and the new knowledge associated with it to win similar projects around the world. Ultimately, the knowledge gained should be applicable as well to Canada's growing prefabrication, modularization and shipbuilding industries.