Distribution Center Productivity Improvements Through Scheduling
published in Logistics Magazine May/June 2004

Introduction

Scheduling in manufacturing is a standard practice. However, this is not the case for distribution center operation. Some large retailers may have in-house developed scheduling applications, or some WMS may include scheduling component, but these are the exceptions.  Recently, a few PC based, and inexpensive distribution center scheduling software packages become available. They interface with and complement WMS. The article shows what can be scheduled, how it is done, and what are the savings.

Inbound appointment booking and outbound scheduling are presented. For each the goal, constraints, manpower planning, and savings are qualified.  In nutshell, the savings come from adjusting the manpower level to workload, from better visibility of scheduling information, and from having time based schedule.  The last shows how the daily operation events should happened in time, e.g. an outbound shipment loading will start at 6 pm and will be ready to go at 8:40 pm. (yellow color on Fig. 1).  The better scheduling software includes automatic scheduling with manual overwrite to handle exceptions.

Fig. 1 A sample of outbound schedule. Columns represent shipping doors, background color like yellow or red indicates a shipment and its status, and the text represents the orders and their loading sequence.

 Automatic Inbound Appointment Booking System

The goal of inbound appointment booking is to give carrier or vendor a date, time, and door number to deliver a shipment. The booking process usually includes verification of the request against purchase order, creating a shipment and an appointment. Some of the goals and constrains are receiving working hours, available doors, purchase order due date, spreading the workload evenly within a week and within a day, and carrier preferences. There are two possible solutions for automatic web based inbound booking. One is based on web service and other is based on emails.  The first works like on-line shopping, is more expensive, but you get appointment right away. The second processes template based email with appointment request and replies via email with appointment booking. The system is less expensive, has better events logging, but one gets appointment a few minutes or a few hours later.  Both systems produce web pages with bookings, reduce requirements for appointment clerks, improve appointment bookings visibility, and predict manpower requirements. The booking logic, exceptions handling, and interface with the existing systems are the major parts of the implementation. 

 
Outbound Scheduling System

Picking, trailer loading, and delivery are the components of outbound process and they are executed in that order, but the scheduling is done in reverse. First, orders are grouped into shipments, next shipments are scheduled for loading, and next picking is scheduled. Knowing the available people or time, the scheduling software calculates the timelines and people allocation to picking zones and shipping docks. Some of the benefits of outbound scheduling are higher productivity, less overtime, and better adjusting staffing to workload level.

Scheduling Information Visibility and Reporting

Up to recently, the scheduling information was dissipated by printing reports. Now, the scheduling software usually created web pages that are available over LAN or Internet. Let takes an example. A logistic company located in Vancouver handles shipments from Far East using Cross Dock Scheduling Software. The software generates web pages with schedule of loading outbound shipments. The pages are available in the DC and to the DCs expecting the shipments, which are distributed throughout the country. If needed, printing is done locally, from a web browser.

Future Enhancements

The need for including progress monitoring into scheduling software is growing. The source of the progress data is the major part of that. There are a few possibilities. Some of them are WMS log files or direct input from the people doing the work.

For inexpensive off-the-shelf  scheduling software by Minidata click  www.maxscheduler.com

Feliks Gadzinski
Founder of Minidata
(905) 276-2717
www.minidata.ca