Forecasting, Planning and Scheduling http:www'managementsupport'com

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Forecasting, Planning and Scheduling
http//www.managementsupport.com
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Outline

• Forecasting
• Planning
• Scheduling
• MRP ERP

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Strategy and Issues During a Products Life
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Forecasting Approaches
Qualitative Methods
Quantitative Methods

• Used when situation is vague little data exist
• New products
• New technology
• Involves intuition, experience
• e.g., forecasting sales on Internet

• Used when situation is stable historical data
  exist
• Existing products
• Current technology
• Involves mathematical techniques
• e.g., forecasting sales of color televisions

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Overview of Qualitative Methods

• Jury of executive opinion
• Pool opinions of high-level executives, sometimes
  augment by statistical models
• Delphi method
• Panel of experts, queried iteratively
• Sales force composite
• Estimates from individual salespersons are
  reviewed for reasonableness, then aggregated
• Consumer Market Survey
• Ask the customer

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Relationships of the Aggregate Plan
Product Decisions
Process Planning Capacity Decisions
Demand Forecasts, orders
Work Force
Raw Materials Available
Inventory On Hand
Aggregate Plan for Production
External Capacity Subcontractors
Master Production Schedule, and MRP systems
Detailed Work Schedules
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Choosing a Scheduling Method

• Qualitative factors
• Number and variety of jobs
• Complexity of jobs
• Nature of operations
• Quantitative criteria
• Average completion time
• Utilization ( of time facility is used)
• WIP inventory (average jobs in system)
• Customer waiting time (average lateness)

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Priority Rules for Dispatching Jobs
FCFS

• First come, first served
• The first job to arrive at a work center is
  processed first
• Earliest due date
• The job with the earliest due date is processed
  first
• Shortest processing time
• The job with the shortest processing time is
  processed first
• Longest processing time
• The job with the longest processing time is
  processed first
• Critical ratio
• The ratio of time remaining to required work time
  remaining is calculated, and jobs are scheduled
  in order of increasing ratio.

EDD
SPT
LPT
CR
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Inputs to the Production Plan
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MRP Benefits

• Increased customer satisfaction due to meeting
  delivery schedules
• Faster response to market changes
• Improved labor equipment utilization
• Better inventory planning scheduling
• Reduced inventory levels without reduced customer
  service

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Distribution Resource Planning

• DRP requires
• Gross requirements, which are the same as
  expected demand or sales forecasts
• Minimum levels of inventory to meet customer
  service levels
• Accurate lead times
• Definition of the distribution structure