KSU MANGT 421 FINAL EXAM MINICK

The Objective of Aggregate Planning?

The objective of aggregate planning is usually to meet forecast demand while minimizing cost over the planning period.

What are the aggregate planning options

Changing Inventory Levels.

Vary workforce size by hiring or layoffs

Varying production rates through overtime or idle time.

Subcontracting

using part time workers

Influencing demand

Back ordering during high demand periods

counter seasonal product and service mixing

A mixed strategy may be the best way to _____________________

Minimize Costs

Chase Strategy

match output rates to demand forecast for each period.

Vary workforce levels or vary production rates.

Minimize inventories and produce only what sales are.

Favored by many service organizations.

Level Strategy

Daily production is uniform.

Use inventory or idle times as buffer.

Stable production leads to better quality and productivity.

Bills of Material

List of components, ingredients, and materials needed to make a product.

Forward Scheduling

Starts as soon as the requirements are known.

Produces a feasible schedule though it may not meet due dates.

Frequently results in build up of work in process inventory.

Backward Scheduling

Begins with the due date and schedules the final operation first.

Schedule is produced by working backwards through the processes.

Resources may not be available to accomplish the schedule.

Finite Loading

Assigns work up to the capacity of the workstation.

All work gets done.

Due dates may be pushed out.

Infinite Loading

Does not consider capacity.

All due dates are met.

Capacities may have to be adjusted.

Sequencing Jobs

Specifies the order in which jobs should be performed at work centers.

Priority Rules

Used to dispatch or sequence jobs.

FCFS: First Come First Serve

SPT: Shortest Processing Time

EDD: Earliest Due Date

LPT: Longest Processing Time

Shortest Processing Time (SPT)

Does well on minimizing flow time and number of jobs in the system.

SPT moves long jobs to the end which may result in dissatisfied customers.

First Come First Serve (FCFS)

Does not do especially well (or poorly) on any criteria but is perceived as fair by customers.

Earliest Due Date (EDD)

Minimizes maximum lateness.

Good production systems require that managers address three issues that are pervasive and fundamental to operations management:

Eliminate Waste, Remove variability, and Improve throughput

Eliminate Waste

Waste is anything that does not add value from the customer point of view.

Storage, Inspection, Delay, Waiting in queues, and defective products do not add value and are 100% waste.

Ohno's Seven Wastes

Overproduction, Queues, Transportation, Inventory, Motion, Over processing and Defective Products.

The Five S's

Sort/Segregate: When in doubt, throw it out.

Simplify/Straighten: Methods analysis tools.

Shine/Sweep: Clean daily

Standardize: Remove variations from processes

Sustain/Self-Discipline: review work and recognize progress.

Variability

Any deviation from the optimum process

Sources of Variability

Poor production processes resulting in improper quantities, late, or non-conforming units.

Unknown customer demands.

Incomplete or inaccurate drawings, specifications, or bills of material.

Manufacturing Cycle Time

The time between the arrival of raw materials and the shipping of the finished order.

Just In Time (JIT)

Materials arrive where they are needed when they are needed.

Identifying problems and driving out waste reduces costs and variability and improves throughput.

Requires a meaningful buyer-supplier relationship.

Kanban

Japanese word for card.

The card is an authorization for the next container of material to be produced.

A sequence of Kanbans pulls materials through the process.

Lean Operations

Broader than JIT in that it is externally focused on the customer.

Starts with understanding what the customer wants.

Optimize the entire process from the customer's perspective.

The objective of maintenance and reliability

maintain the capability of the system

Maintenance

All activities involved in keeping a system's equipment in working order.

Reliability

The probability that a machine will function properly for a specified time.

Important Maintenance Tactics

Implementing or improving preventative maintenance.

Increasing repair capability or speed.

Important Reliability Tactics

Improving individual components.

Providing redundancy.

Preventative Maintenance

Routine inspection and servicing to keep facilities in good repair.

Breakdown Maintenance

Emergency or priority repairs on failed equipment.

Problems with Breakdown Maintenance

Might be okay for low criticality equipment or redundant systems.

Could be disastrous for mission-critical plant machinery or equipment.

not permissible for systems that could imperil life or limb (Like aircraft).

Problems with Preventative Maintenance

Scheduled replacement or adjustment of parts/equipment with a well-established service life.

Predictive Maintenance

Using advanced technology to monitor equipment and predict imminent equipment failures.

Visual inspection and/or scheduled measurements of vibration, temperature, oil and water quality.

Measurements are compared to a "healthy" baseline.

Equipment that is trending towards failure can be scheduled for repair.

Predictive Maintenance Tools

Vibration analysis, infrared thermography, oil and water analysis.