The little blue session on scheduling

“Scheduling is where the rubber meets the road” - Mike Liddell (ML)

“Everyone has a plan until they get hit”

– Mike Tyson

“Unless a scheduling system has the built in logic to model real world business

constraints, it is of no use because it will give faulty information”

– ML

“Many companies stay in business by building in huge, expensive buffers”

- ML

1. The ability to schedule more accurately at the machine level as opposed to the

work center level and to assign different shifts and run speeds for each machine.

2. The ability to schedule each machine finitely or infinitely.

3. The ability to schedule using multiple constraints (such as tooling and operators).

4. The ability to calculate sequence dependent setup times.

5. The ability to schedule precisely (minutes or seconds) as opposed to time

buckets (usually days or weeks).

6. The ability to integrate easily with other systems like ERP and Shop Floor Data

Collection (SFDC).

7. The ability to sequence orders based on due date, priority or some other

attribute.

8. The ability to schedule quickly (minutes or seconds) and maintain a real-time

view of the schedule.

9. The ability to easily make changes such as adding new orders, changing

priorities, adding machine downtimes or completing operations.

10.The ability to synchronize the schedule with material constraints.

Two Kinds of Manufactures:

1. The make-to-stock (MTS) manufacturer◦ Selling inventories

◦ Group demands into long runs

◦ Relies on inventories and time buckets

◦ ERP (Enterprise Resource Planning) Systems are the

tool of choice; these tool, however, cannot

help prioritize

estimate the promise date of new orders

synchronize material and capacity constraints

“Like driving a car with your eyes closed; the only time you know

you have a problem is when you hit something.” – ML

Two Kinds of Manufactures:

2. The make-to-order (MTO) manufacturer ◦ Selling capacity

◦ Making excess inventory consumes materials and

capacities, making on-time deliveries more difficult

◦ Lean business model

◦ APS (Advanced Planning and Scheduling) Systems are

the tool of choice. H/Sched is one such tool.

“Scheduling is the brain center that drives the operations side of a

manufacturing company.” – ML

The MTO/APS manufacture still

needs an MTS/ERP planning system

Without a planning process the MTO manufacture

may quickly find that there will be times when his

capacity is consumed by low priority orders

“A scheduling system is like a GPS, it will help us get where we want

to go but it won’t tell us where we want to go.” – ML

“A planning system is like a map, it shows us where we want to go,

but cannot account for obstructions along the way” – DT

So just as a map is an overall trip guide, but cannot give us actual turn-

by-turn instructions along the way - an ERP system should be used to

guide and set the objectives of the APS system, but then let the APS

system get us there.

1. They must handle the level of detail needed to model real world

constraints such as operators and tooling or the ability to calculate

sequence dependent setup times based on multiple product attributes

that may be unique to each company.

2. They must be able to provide advanced functionality, such as custom

sequencing rules, for schedulers who want to get additional benefits

from their systems.

3. They need to be easily customized and modified (think Excel) so that

they can meet the changing requirements of a business without being

orphaned when new versions are released.

“Because most people are comfortable with Excel and it usually doesn’t

cost anything, it often becomes the drug of choice. Like so many other

drugs, however, the side effects can make things much worse and

sometimes even fatal.” – ML

“Excel can create a valid schedule. For that matter a patient person can put

together a valid schedule using cards and a wall. The big problem is the

enormous output of time and energy it takes to update that schedule every

time something changes because, as we know, things change all day and

every day” – ML

“Home-grown EXCEL systems are our biggest competition.” – DT

Two Options Mike Gives:

1. Hire a number of people totally dedicated to manually updating your

schedule several times a day, or

2. Buy a system that does all of that in just a few seconds, every day.”

“The schedule should be automated

to do all the donkey work (the 80%)

but allow the scheduler to use his or

her experience to fine tune the

schedule (the 20%)” – ML

80+% of scheduling is pure simulation.

The 20-% that includes optimization is

often better left to experienced

schedulers.

Developing an

APS System

The Ten Biggest Mistakes Made Implementing Scheduling Systems

1. Not setting up for success. How is success to be measured? Be realistic.

2. Buying a software package because someone else did. Bigger isn’t always better; just ‘cause it worked for Joe ...

3. Trying to “do it yourself”. Like performing surgery on yourself.

4. Buying an “integrated” solution because it is integrated. The appearance of integration is only the tip of the iceberg; no one-size-fits-all.

5. Too much design/not enough testing. Move quickly to prototyping.

6. Letting “better” be the enemy of a good solution. 80/20 rule; simulation vs. optimization.

7. Forgetting that all customers are not created equal. No common denominator; over generalized systems fail many customers.

8. Did I mention not doing enough testing? Beyond “does the software work?”; testing with “scripts”.

9. Failing to train adequately. Don’t rely on schedulers figuring out system capabilities on their own.

10.Believing that successful implementation is the end. Improving scheduling and customer service is an ongoing challenge.

Scheduling Break Out Session -- Lube Block Flow Diagram

Mode 1 (20 days per month)Mode 2 (10 days per month)!! Minimize mode switches !!

** Three day minimum run length on any stock (the longer each run the better)

All Inventories: 50 MB Maximum each stockAll non-lube product streams not shown go to FCC feed

**

Furf

Two

15

MBD

**

DeWax

10

MBD

Minimize

Light to

Heavy

Stock

changes

PDA

10 MBD

XLX

LX

BS

HX

LN

HN

XHN

DWBSXHX

DAO

LGO

XLGO

XHGO

HGO

XLN

CDU

Arab Light100 MBD

15.0%

10.0%

10.0%

5.0%

25.0%

60.0%

50.0%

40.0%

40.0%

60.0%

50.0%

75.0%

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85.0%

80.0%

75.0%

**

Furf

One

10

MBD

20.0%

Lube PlantRunout Spreadsheet Exercise

The little blue session on scheduling

Technology

Transcript of The little blue session on scheduling