Chapter 6

Lean manufacturing

a means of achieving high levels of customer service with minimal inventory investment

assembly line balancing

assigning all tasks to a series of workstations so that the required cycle time is met and idle time is minimized

Make-to-order

product is built directly from raw materials and components in response to a specific customer order customer order decoupling point could be in either "raw materials at the manufacturing site" or the "supplier inventory e.g. airplanes

Efficiency

sum of task times (T)/actual number of workstations(Na)xWorkstation cycle time (C)

Lead time

the time needed to respond to a customer order

Production Process Mapping

-Develop a high-level map of a supply chain process -Useful to understand how material flows and where inventory is held -First step in analyzing the flow of material through a production process

Manufacturing Cell Layout

A dedicated area where products that are similar in process requirements are produced Cells are designed to perform a specific set of processes Dedicated to a limited range of products

Days-of-supply

A measure of the number of days of supply of an item

Make-to-stock

A production environment where the customer is served "on-demand" from finished goods inventory. balance the level of inventory and customer service to satisfy customers e.g. television, clothing

Inventory turn

An efficiency measure where the cost of goods sold is divided by the total average value of inventory

Assembly Line and Continuous Process

Area where an item is produced through a fixed sequence of workstations, designed to achieve a specific production rate A process that converts raw materials into finished product in one contiguous process

Workcenter Layout

Most common approach to developing this type of layout is to arrange workcenters in a way that optimizes the movement of material Optimal placement often means placing work centers with high levels of interdepartmental traffic adjacent to each other Sometimes is referred to as a job shop and is focused on a particular type of operation

Assemble-to-order

Preassembled components, subassemblies, and modules are put together in response to a specific customer order primary task is to define a customer's "order in terms of alternative components", since these are carried in inventory e.g. Laptops

Reducing Task Time Possibilities

Split the task - Can we split the task so that complete units are processed in two workstations? Share the task - Can the task be shared so an adjacent workstation does part of the work? Use parallel workstations Use a more skilled worker Work overtime Redesign - It may be possible to redesign the product to reduce the task time

Engineer-to-order

The firm works with the customer to design the product, which is then made from purchased material, parts, and components e.g. buildings

Little's Law

The flow of items through a production process can be described using Inventory = Throughput rate × Flow time Inventory - materials held by the firm Throughput - long-term average rate that items are flowing through the process Flow time - time for a single unit to completely flow through the entire process

Customer order decoupling point

The point in the supply chain where inventory is positioned to allow the preceding processes to operate independently is the

Total average value of inventory

The total investment in inventory at the firm: -Raw materials -Work-in-process -Finished goods

Production processes

are used to make any manufactured item Step 1 - Source the parts needed Step 2 - Make the product Step 3 - Deliver the product

workstation cycle time (C).

production time per day/required output per day