Strategic Capacity Management Dr. Ron Lembke Operations Management

Maximum Throughput of a Process What is the capacity of the system? Should we add any capacity? How should we run the system? Where should we keep inventory? 50/hr 20/hr10/hr 40/hr

Maximum Throughput of a Process What is the capacity of the system? Convert to units / hr 6 min 5 min 4 min 5 min 10/hr 12/hr 15/hr 12/hr

PRODUCTIVITY MEASUREMENTS

Productivity Productivity = Outputs / Inputs Partial:Output/Labor or Output/Capital Multifactor: Output / (Labor + Capital + Energy ) Total Measure: Output / Inputs

Automotive Productivity Book Data: Jaguar: 14 cars/employee Volvo: 29 cars/employee Mini: 39 cars/employee

US Productivity Growth Source: Bureau of Labor Statistics

Total Factor Productivity Increases Take labor and capital into account percentage increase in output that is not accounted for by changes in the volume of inputs of capital and labour. Source: Economist, 2009

Growth of Service Economy % of Labor Force

U.S. Productivity Gains Services harder to make more productive Product Development team structure (Eg: Chrysler Prowler, Boeing 787) Facilities improvements (less WIP, better quality, flexibility) Keiretsu-like supplier cooperation -- tight cooperation

U. S. Productivity Gains Increased 1.37% per year Increased 2.37% per year Potential sources of productivity gains: Capital investment (1.13%) Labor Quality(0.25%) Technological progress(0.99%) Computers really are making us more productive. Source: WSJ, 8/1/00, Further Gains in Productivity are Predicted, A2

Improving Productivity Develop productivity measurements– you cant improve what you cant measure Identify and Improve bottleneck operations first Establish goals, document and publicize improvements

HOURS WORKED

Hours Worked by Country Source: OECD, 2012 Average

Hours Worked and Productivity Source: Eurofund, European Working Conditions Observatory, 2012

What Would Henry Say? Ford introduced the $5 (per day) wage in 1914 He introduced the 40 hour work week so people would have more time to buy It also meant more output: 3*8 > 2*10 Now we know from our experience in changing from six to five days and back again that we can get at least as great production in five days as we can in six, and we shall probably get a greater, for the pressure will bring better methods. Crowther, Worlds Work, 1926

Forty Hour Week Ernst Abbe, Karl Zeiss optics 1896: as much done in 9 as in 8.

Marginal Output of Time Value of working n hrs is Onda As you work more hours, your productivity per hour goes down Eventually, it goes negative. Better to work b instead of e hrs S.J. Chapman, 1909, Hours of Labour, The Economic Journal 19(75)

Crunch Mode Ea_spouse: 12/04 Pre-crunch SO was working 7 * 13: 91 per week! Maybe time off at 6pm Saturday $5k signing bonus, couldnt quit Class action: April 06 $14.9m Igda.org Why Crunch Mode Doesnt Work: 6 Lessons

Learning Curves time/unit goes down consistently Down by 10% as output doubles We can use Logarithms to approximate this What will our cost per unit be when weve made 10,000 units? If you ever need this, me, and we can talk as much as you want Also, see Appendix B

Example 1 Pauls12345 Bottles Bags Newmans Bottles Bags Demand for each product, by year.

Example 1 Totals12345 Bottles Bags ,0501,180 bottle machines 150k/yr Three currently = 150 * 3 = 450k bag machines 250k/yr Five currently = 250 * 5 = 1,250k

Example 1 Bottles Machines12223 Mach. usage Workers (2 workers per machine) Bags ,0501,180 Machines23455 Mach Usage Workers (3 workers per machine)

Capacity Tradeoffs Can we make combinations in between? 150,000 Two-door cars 120,000 4-door cars

How much do we have? We can only sustain so much effort. Best Operating Level Output level process designed for Lowest cost per unit Capacity utilization = capacity used best operating level Hard to run > 1.0 for long

Time Horizons Long-Range: over a year – acquiring, disposing of production resources Intermediate Range: Monthly or quarterly plans, hiring, firing, layoffs Short Range – less than a month, daily or weekly scheduling process, overtime, worker scheduling, etc.

Service Differences Arrival Rate very variable Cant store the products - yesterdays flight? Service times variable Serve me Right Now! Rates change quickly Schedule capacity in 10 minute intervals, not months How much capacity do we need?

Capacity Levels in Service Zone of non-service < Zone of service Critical Zone Mean service rate, Mean arrival rate, =100% =70%

Adding Capacity Expensive to add capacity A few large expansions are cheaper (per unit) than many small additions Large expansions allow of clean sheet of paper thinking, re-design of processes Carry unused overhead for a long time May never be needed

Reengineering Business Process Reengineering (Hammer and Champy) Companies grow over time, adding plants, lines, facilities, etc. Growth may not end in optimal form Re-design processes from ground up

Capacity Planning How much capacity should we add? Conservative Optimistic Forecast possible demand scenarios (Chapter 11) Determine capacity needed for likely levels Determine capacity cushion desired

Toyota Capacity 1997: Cars and vans? Thats crazy talk First time in North America 292,000 Camrys 89,000 Siennas 89,000 Avalons

Capacity Sources In addition to expanding facilities: Two or three shifts Outsourcing non-core activities Training or acquisition of faster equipment

Decision Trees Consider different possible decisions, and different possible outcomes Compute expected profits of each decision Choose decision with highest expected profits, work your way back up the tree.

Summary Having enough capacity is crucial Measured productivity (single and multi- factor) Increasing productivity key to economic growth and profits Computed number of machines and employees needed Making employees more productive is often cheaper than adding machines