We introduce the visibility graph as an alternative way to estimate the length of a route traveled by order pickers in a warehouse. Heretofore it has been assumed that workers travel along a network of travel paths corresponding to centers of aisles, including along the right angles formed where picking aisles join cross aisles. A visibility graph forms travel paths that correspond to more direct and, we believe, more appropriate “travel by sight.” We compare distance estimations of the visibility graph and the aisle‐centers method analytically for a common traditional warehouse design. We conduct a range of computational experiments for both traditional and fishbone warehouse layouts to assess the impact of this change in distance metric. Distance estimations using aisle‐centers calculates a length of a picking tour on average 10–20% longer compared to distance estimations based on the visibility graph. The visibility graph metric also has implications for warehouse design: when comparing three traditional layouts, the distance model using a visibility graph resulted in choosing a different best layout in 13.3% of the cases.

中文翻译：

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一种用于建模订单拣配路径的新颖方法

我们引入可见性图，作为估计订单拣选员在仓库中行驶的路线长度的另一种方法。迄今为止，已经假设工人沿着与过道的中心相对应的行进路径网络行进，包括沿着在拣选过道与交叉过道相交的地方形成的直角行进。可见度图形成的行进路线对应于更直接的路线，并且我们认为更合适的“视线行驶”。对于常见的传统仓库设计，我们分析性地比较了能见度图和过道中心方法的距离估计。我们针对传统仓库和鱼骨仓库布局进行了一系列计算实验，以评估这种距离度量标准的影响。与基于可见性图的距离估计相比，使用过道中心的距离估计计算出的采摘行程的平均长度要长10％到20％。可见性图度量标准也对仓库设计产生影响：在比较三种传统布局时，使用可见性图的距离模型导致在13.3％的案例中选择了不同的最佳布局。