Operations Fall 2015 Bruce Duggan Providence University College

This Week’s Project Vehicle Salvaging: Process Flowchart Precedence Graph

1 Check for Spare Tire [? min] Is there a spare tire? Is the tire in good shape? yes no yes no yes Is the rim aluminum ? 3 Leave tire on rim [? min] 2 Take it out [? min] yes

4 Put in good tire bin [? min] (from 3)

Summary Many factories use a combination of layouts workcentres for some parts assembly operations for others Service businesses are in many ways similar to manufacturing businesses Service design must consider the high degree of personalization often required the speed of delivery needed the direct customer contact the inherent variability of service encounters 6-20

Know The Answers To These Questions 1. What is the difference between an “assemble to order” process and a “make to order” process? 2. How else, other than an assembly line, can a production process be organized? 3. What calculation can be used to help determine if investing in equipment for a process is worthwhile? 4. Should services be classified by degree of customer contact or by degree of labour intensity? 5. How do you determine the required “pace” (cycle time) for an assembly line and how do you determine how many people are needed to work on the line? 6. How can changing a facility layout reduce waste and increase capacity? 6-21

Organization of Production Processes Project layout The product, because of its sheer volume or weight remains fixed in a location Workcentre A process structure suited for low-volume production of great variety of nonstandard products Manufacturing cell An area where simple items that are similar in processing requirements are produced 7-3

Organization of Production Processes Assembly Line A process structure designed to make: o discrete parts o moved through a set of specifically designed workstations o at a controlled rate Continuous process An automated process that converts raw materials into a finished product in one continuous process. Similar to assembly line, but the flow is continuous, not discrete.

Product-Process Matrix

Break-Even Analysis A standard approach to choosing among alternative processes or equipment Model seeks to determine the point in units produced (and sold) where we will start making profit on the process or equipment Model seeks to determine the point in units produced (and sold) where total revenue and total cost are equal 7-6

Break-Even Analysis Formula This formula can be used to find any of its components if the other parameters are known break-even demand= purchase cost of process or equipment total fixed costs of process or equipment price per unit cost per unit unit price to customer variable cost per unit

Break-Even Analysis Example Suppose you want to purchase a new computer that will cost $5,000. It will be used to process written orders from customers who will pay $25 each for the service. The cost of labour, electricity and the form used to place the order is $5 per customer. How many customers will we need to serve to permit the total revenue to break-even with our costs? break-even demand= total fixed costs of process or equipment$5,000 = 250 customers unit price to customer variable cost per unit $25$5

Designing a Production System Project Layout Visualize the product as a hub of a wheel, with materials and equipment arranged concentrically around the production point. Workcentres Arrange workcentres in a way that optimizes the movement of material.

Designing a Production System Workcentre Layout

Designing a Production System Manufacturing Cell Group parts with common machine requirements into families. Identify dominant flow patterns for each part family. Machines and the associated processes are physically grouped into cells.

Designing a Production System Manufacturing Cell

Designing a Production System Assembly Line Layout Assembly line layout design is for the special purpose of building a project by going through a series of progressive steps or ‘stations’ Stations are linked by a material-handling device. There is usually some form of pacing by which the amount of time allowed at each station is managed.

Designing a Production System Continuous Process Layout Continuous or flow process is similar to an assembly line except the product moves continuously through the process.

Classification of Services Service systems Generally classified according to: o who the customer is o the service provided to them Customer is involved in the production process Service systems with a high degree of customer contact are more difficult to control than those with a low degree of customer contact

Service-System Design Matrix

Assembly Line Balancing 1.Specify the sequential relationships among tasks. 2.Determine the required workstation cycle time. 3.Determine the theoretical minimum number of workstations. 4.Assign tasks, one a time, until the sum of the tasks is equal to the workstation cycle time. 5.Evaluate the efficiency of the balance. 6.Rebalance if needed.

Assembly Steps and Times: Vortex Hybrid Sedan

Precedence Graph: Vortex Hybrid Sedan

Line Balancing Process: Vortex Hybrid Sedan

Precedence Graph: Vortex Hybrid Sedan

Possible Physical Layout of an Assembly Line

Flexible Line Layouts

End of Chapter 7