Line Efficiency

How do you calculate theoretical time?

# of shifts * 60 minutes

For a line running a product valued at $2/unit and a line speed of 120 cmp, what is the cost of downtime

$240/min, or >$14,000/hr

What drives manufacturer's nuts in trying to plan their operations?

* Competition - both foreign and domestic, is pushing manufacturers to reduce costs and improve productivity * Customers - they are demanding more variety

Quality is a fraction that is __ ___ the waste

1 minus

What are two methods to select the appropriate machine capacity?

1. Increase capacity of each machine in the downstream direction - jams stop the entire line - line empties out after the jam is corrected 2. Key Machine approach to line planning - Capacity of key machine is equal to or greater than the planned line capacity - Higher capacity machines upstream and downstream - Should also look for the limiting piece of equipment

What are 4 things machine efficiency depends on?

1. Operator decisions (based on skill and knowledge) 2. Machine maintenance (clean, in good repair) 3. Container characteristics (round, PE consistency) 4. Environmental issues like weather (temp., humidity, etc.)

What are two ways to minimize changeover time

1. SMILE 2. Schedule and plan changeovers - have personnel ready, have required parts ready, keep record of machine settings, use machine automatic changeover (Note that changeover times can vary widely)

What are the dimensions and capacity for a "large size" accumulator

10' x 14' ~2800+ aluminum cans

Example of throughput

240 pkg/minute (expected) * 97% efficiency = 230 pkgs/min (actual)

If a machine/system runs 50% effective with 1 operator and becomes 65% effective with 2 operators, the effectiveness goes up ___%, and the efficiency is dropped to ___% based on labor

30%, 50%

What are the dimensions and capacity for a "small size" accumulator

4' x 4' ~ 290 aluminum cans

A perfect bottle could have 100% quality, but if half have to be thrown away because of defects, the quality yield is only ___%

50% (AKA you are 100% effective, but only 50% efficient)

What is the Industry Productivity Index?

72.3%

What is the equation for Quality

Actual Good Product / Product Output

What is the equation for performance?

Actual speed dr / Normal Speed

What is the equation for OEE?

Availability x Performance x Quality Or B/A x D/C x F/E

What is the best location for an accumulator?

Before or after key machines or both - you really never know until trial and error Depends on floor space, reliability, capabilities If you have 1 min of line time, that gives 1 min of line time to repair any breakage

What are the three main causes of downtime?

Changeover, maintenance, and stoppages

What are causes of downtime?

Changeovers, supply interruptions, packaging components, product interruptions or changes, maintenance, cleaning, stoppages and line jams, power failures, operator absences

What is the only workable approach?

Computer modeling and simulation

Effectiveness is the relation between what ____________ at the end of a process and what _________ at the end of a process

Effectiveness is the relation between what THEORETICALLY COULD BE PRODUCED at the end of a process and what ACTUALLY CAME OUT/WAS PRODUCED at the end of a process

How can you keep manufacturing costs to a minimum?

Extend production runs to minimize the cost per unit

T/F: During downtime, there is little production

False, NO production

How can you minimize stoppage time?

Have a plan in place (Plan for Failure) to fix jams, breakages, machine failures Who - is doing the work What - work needs to be done When - will it be done Where - it will be done

What are two things high OEE numbers are indicative of?

High schedule fulfillment Optimized labor

Example of effectiveness

If you machine or system is capable of making 100 quality products an hour, and it only makes 70, then it is 70% effective (but we don't know how efficient b/c we don't know what we had to put in)

What is the Key Machine approach

Increased the probability of adequate supply to the key machine Decreases the probability of blockage of output from the key machine

What are three costs of downtime?

Inventory Lost production capacity Employee costs

OEE is the rate between what two things?

It's the rate between what a machine theoretically product and what it actually did

What is computer modeling and simulation?

Known or assumed probabilistic patterns of machine operation and failure Run a simulation many times Vary the size and locations of accumulators and other components

How can you reduce plant operation costs?

MAXIMIZE production runs (uptime) MINIMIZE changeover, maintenance, and stoppages

What are two "reality checks"

Machines may not preform at the predicted efficiency or capacity Machines of the desired capacity may not be available (purchase next larger or multiples of same)

Effectiveness is: Making ____ Making ____ Making ____

Making the right things - the right product or SKU at the right speed (PERFORMANCE) Making it the right way - no rework, no defects, no waste (QUALITY) Making it at the right time - producing as planned, minimizing time losses (AVAILABILITY)

What are six ways to maximize uptime?

Minimize production time used for maintenance - schedule it during off hours and regular inspections Monitor the ongoing production process - might use Statistical Process Control (SPC) to tell when parts are about to wear out or need replacing Minimize stoppage time (see how on next card) Use accumulators and conveyors Update the controls Consider if a new(er) machine is appropriate for this need

What is redundancy?

Multiple machines instead of one high capacity machine Various management approaches Use simulation to better understand the situation

What are the bold headings in the reading - How to Calculate Overall Equipment Effectiveness: A Practical Guide

OEE Overview and Efficiency versus Effectiveness A simple example The A-P-Q's of OEE Availability Performance Quality Time Equals Money The Straightforward approach to OEE A practice definition of OEE Scope of Analysis OEE and the cost of quality The concept of Downtime as understood in availability A proven technique in manufacturing comes to packaging

Formal definition of OEE 2

OEE is defined as the product or cost function or interplay of all availability or uptime of the operative mode multiplied by the performance or actual resultant production speed (from actual dialled rate and ramping rates) divided by the normal or steady state speed and then multiplied by the quality or the output of quality product divided by the input of the critical component or aggregate of all the inputs (components consumed, lost, reworked, destroyed or unaccounted for during the production process).

Formal definition of OEE

OEE is the Overall Equipment Effectiveness of a defined production process during the defined operative period or mode in which all activities related to production, personnel and inputs are accounted for during all producing or dependent activities within a defined scheduled time or operative mode time.

How much production time is OEE typically calculated for?

One week's or one month's production of a given size and product (smaller slices might not give enough info) Looking at less than 10,080 minutes (one week) of operating time isn't significant

What does OEE stand for?

Operational Equipment Effectiveness

Why is there employee cost for downtime?

People get paid for standing/sitting around

What are the two parts downtime is broken into?

Planned downtime and unplanned downtime (changeover and maintenance are planned, stoppages are unplanned)

Yield is also known as what?

Quality (basically saleable product)

What is the efficiency ratio of a single machine?

Ratio: Actual time worked/theoretical time worked

What is the equation for availability?

Run time / Total operative mode time

What does SMILE stand for?

Setup Minimization to Improve Line Efficiency (it is like the "pit crew" of the packaging world)

What are the benefits of the key machine approach?

Smaller capacity machines Lower capital expense Less floor space required

What is the "Cost of Quality"?

The cost of not creating a quality product or service

What is production schedule time?

The time period in which allotted defined products are to be produced

What is the equation for throughput?

Theoretical Processing Speed (expected) x Efficiency of Machine Theoretical Processing Speed (expected) is NOT the speed the machine can run - the machines would wear

What are planned events defined as?

Those events which no output of saleable product results and which management has control over the timing and extent of the activity Ex. holidays

What can OEE do when broken into its three main components?

Track down where we lost bad product (If we run 50% OEE everyday, we can lose units in three different ways, and every loss has its own cost structure)

T/F: There is NO known way to determine the best size, or locations, analytically, for an accumulator

True

T/F: Two accumulators is always better than one

True

T/F: Adding another independent machine or multiple independent machines to an existing will ALWAYS lower the line efficiency

True (assumes that no machine runs at 100% efficiency)

T/F: Efficiency varies from day to day

True (most downtime on Mondays and Fridays)

What is more critical, uptime or downtime?

Uptime

Example of efficiency ratio

[(# of shifts x 60 minutes) - downtime] / (# of shifts x 60 minutes)

What is the ratio of Actual to Theoretical Production

[Actual output / (# of shifts x 6o minutes x rated capacity)] * 100

What is the ratio of Actual to Theoretical at a Particular Production Rate

[Actual output / (# of shifts x 6o minutes x set capacity)] * 100

What helps to run downstream machines?

accumulators and conveyors

What did the PMMI study look at?

average efficiencies for types of machines a specified set of (9) machines the calculated efficiency of the combination of machines

OEE has been around for ___

decades in it's elemental form

What is Packaging Line Efficiency?

efficiencies of single machines, system of machines, and issues that influence system efficiencies

Efficiency is typically ___ at lower speed setting

higher

What is predictive

likelihood that something will fail

Inventory reduction is the major benefit of ___ ___

minimal downtime

What are Secondary Machines (SM)?

minor unit ops that convey, manipulate, collate, inspect, code or mark the package such as conveyors, combiners, dividers (when separate from a primary unit op), coders (laser, inkjet, impression, etc.), checkweighers, X-ray, Gamma inspection, independent fill, cap or label detection, rejection units

The actual ___ ___ equals the theoretical speeds, and, as a result, the output is never as high as it is planned to be

never equaals

What is preventative maintenance

prevents something bad from happening, like oil spills, tighten screws

What is rework considered within?

quality

OEE is purely ___ based

time (time converted)

What are Primary Machines (PM)?

unit ops that are capital equipment that has a direct involvement in assembling the package such as unscramblers, rinsers, fillers, cappers, labelers, cartoners, case packers, palletizers, etc

What is Actual output?

what occurs with stoppages. i.e., 273 cpm due to production downtime

What is Theoretical output?

what you will set the line to run. i.e., 300 containers per minutes

If any asset is removed from the process in such a way as to make the process for a given product not viable then the expected OEE number is considered ____

zero (total recall also yields zero)