{"id":327262,"date":"2018-09-25T12:00:39","date_gmt":"2018-09-25T19:00:39","guid":{"rendered":"http:\/\/www.esri.com\/arcgis-blog\/?post_type=blog&p=327262"},"modified":"2019-02-21T13:43:26","modified_gmt":"2019-02-21T21:43:26","slug":"fleet-routing-with-the-vrp-solver-time-windows","status":"publish","type":"blog","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/network-analyst\/transportation\/fleet-routing-with-the-vrp-solver-time-windows","title":{"rendered":"Fleet Routing with the VRP Solver: Time Windows"},"author":8262,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"_acf_changed":false,"_searchwp_excluded":""},"categories":[23351],"tags":[231602,31681,231592],"industry":[],"product":[37021],"class_list":["post-327262","blog","type-blog","status-publish","format-standard","hentry","category-transportation","tag-fleet-routing","tag-network-analysis","tag-vrp","product-network-analyst"],"acf":{"short_description":"This article will discuss the basics of time windows in the VRP solver as well as how to prioritize their importance.","flexible_content":[{"acf_fc_layout":"content","content":"

More and more companies need to incorporate appointment times or time windows into their routing solutions.\u00a0 The 30-minute guarantee isn\u2019t just for pizza delivery anymore.\u00a0 We will discuss the basics of time windows in the VRP solver and how to prioritize their importance.<\/p>\n

The Basics<\/h3>\n

Time windows are a way to indicate when the route\/driver should arrive at that order location.\u00a0 The VRP Solver supports two time windows per order.\u00a0 If the beginning time for a time window is left null, then it will correspond with starting at the earliest start time of the earliest route.\u00a0 Similarly, if the ending time for a time window is left blank, then it will correspond with the latest ending of the last route.<\/p>\n

Unless using the Rest Request system, the time window fields are set up to accept either just time or time and date.\u00a0 If it is just the time then it is assumed to be on the default date.\u00a0 If using both date and time be sure to use both date and time in all time fields in Orders, Depots, Routes, and Breaks.\u00a0 The Rest Request system requires that all times are in milliseconds since epoch (which is January 1st<\/sup> 1970).\u00a0 It, therefore, will inherently have both date and time.<\/p>\n

.<\/p>\n

Note: Time windows do not include when the drivers should be done at that location, ready to go to the next location.\u00a0 It is only when they should arrive at the location.\u00a0 If you need to model it so that the driver leaves within a certain time, then for your time windows subtract the service time from the TimeWindowEnd value. This allows for if the driver was to show up right at the end of this modified time window they would be completed with the service time and leaving right at the end of the original time window.<\/p>\n

Hard vs. Soft Time Windows<\/h3>\n

Hard time windows mean that the route\/driver must show up during the designated time frame of the time windows.\u00a0 A soft time window, on the other hand, allows the route\/driver to show up late but the violation is penalized in the solver so that violation times are minimized.\u00a0 To indicate that the time window is hard set the corresponding MaxViolationTime to zero.\u00a0 Leaving this value as null makes it a soft time window.\u00a0 Giving a positive value for MaxViolationTime makes it a soft time window within a hard time window.\u00a0 This means the route\/driver can be late to that location, incurring the violation penalty, but only up to the MaxViolationTime.\u00a0 At that point it is a hard time constraint.<\/p>\n"},{"acf_fc_layout":"image","image":{"ID":327272,"id":327272,"title":"TimeWindows","filename":"TimeWindows.jpg","filesize":35934,"url":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/network-analyst\/transportation\/fleet-routing-with-the-vrp-solver-time-windows\/timewindows","alt":"Time window fields in the orders attribute table","author":"8262","description":"Shows different time window options in the orders attribute table of the VRP solver.","caption":"","name":"timewindows","status":"inherit","uploaded_to":327262,"date":"2018-09-25 15:48:04","modified":"2018-09-25 15:49:27","menu_order":0,"mime_type":"image\/jpeg","type":"image","subtype":"jpeg","icon":"https:\/\/www.esri.com\/arcgis-blog\/wp-includes\/images\/media\/default.png","width":949,"height":237,"sizes":{"thumbnail":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","thumbnail-width":213,"thumbnail-height":53,"medium":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","medium-width":464,"medium-height":116,"medium_large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","medium_large-width":768,"medium_large-height":192,"large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","large-width":949,"large-height":237,"1536x1536":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","1536x1536-width":949,"1536x1536-height":237,"2048x2048":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","2048x2048-width":949,"2048x2048-height":237,"card_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","card_image-width":826,"card_image-height":206,"wide_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2018\/09\/TimeWindows.jpg","wide_image-width":949,"wide_image-height":237}},"image_position":"center","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"content","content":"

Prioritizing Time Window Violations or Total Cost<\/h3>\n

When setting up a problem with soft time windows you have the option to identify how much priority you want to place on minimizing the time window violation time vs minimizing the total cost of the routes (which includes the total time and total distance for all of the routes).\u00a0 These two priorities are usually working against each other.\u00a0 Minimizing or eliminating time window violations usually requires higher costs because.\u00a0 This is because the shortest tour amongst all of the stops will likely not satisfy the time windows.\u00a0 To indicate the preference for the VRP problem use the parameter Time Window Violation Importance.\u00a0 There are three options for this parameter: Low, Medium, and High.<\/p>\n