Robot Shift

Automation is a risky business.  You’re designing machines to do the job of people and that can be a tough task (see my post How To Automate A Complex Manual Process).

The main challenges or risks with any automation project fall into three categories: 

1)  Can you go fast enough to keep up? (Throughput/Speed)

 2)  Can you find the parts, pick them up, and place them accurately all while not dropping or damaging them? (Locating and Gripping Strategies)

3)  Can you ensure quality will remain in the process without people there? (Quality Checks)

The devil is in the details.  I’ve seen countless projects go sideways because integrators made assumptions about these variables and they came back to bite them.  You don’t want a science fair project on your floor.

Great integrators are up front and realistic about the risks of projects and have tools/strategies to mitigate these risks.  Kinematic simulation software can be used to determine robot move times very accurately.  Discrete-Event simulation software can plug these robot speeds in with the entire process to get an understanding of the total process throughput/flow (i.e. fork-truck traffic, CNC cycletime, etc.).  Prototyping of grippers or gripping strategies ensures you can grab the parts and handle as required.  Prove out the quality checks.  What tools/technologies will be used to solve this and how well will they work?

Have them show you similar projects they’ve completed successfully using similar strategies/technologies.

…more to come.

Most manufacturers that are new to automation don’t know what they don’t know.  They often select the first or second vendor they talk to, and end up disappointed.  I was reminded of this this week when a new client was introduced to us with the hopes we could fix a number of their outstanding issues that another integrator didn’t/couldn’t finish.  From an integration side, it’s frustrating to compete with integrators that over promise and under deliver.  They often over-simplify and underestimate complexities and risks.

I thought I’d put together my Letterman-style Top 10 List of criteria to select an integrator.  These can be used as a checklist to make sure you’ve got someone who’s the real-deal.  Here’s #10…

#10.  They Know Their Value Proposition 

Another way of saying this is What are they better at than anyone else?  Every company has strengths and weaknesses. If an integrator can’t articulate their value proposition to you – they don’t understand themselves.  Average companies claim to be good at everything.  Great companies are focussed and know where they fit and where they don’t.   You don’t want average.

…more to come.

The natural thinking, when you automate something, is to take a robot and try to have it mimick the tasks a person does when they do the process.  The challenge is, a person has a pretty complex controls system. A robot doesn’t. 

Think about the tools and processes a person uses unconsciously when they perform a task:

• As a person moves to pickup a part, they adjust the speed and position of their hands using their eyesight based on where the part is and where their hands are  (think of catching a baseball).  This is light-years beyond what a robot can do.
• A person has thousands of nerve-endings (sensors) and two hands that serve as phenomonal grippers.
• A person uses force-feedback to ‘feel’ what they are doing.  A person can sense where an object’s centre of mass is and if they’ve grabbed it correctly.
• Finally, a person has intuition.  A person unconsciously processes all this data and gets a gut feel that something is wrong when something doesn’t feel, look, or sound right.

All these abilities, that a person inherently has, make it easy for a person and very challenging for automation to handle complex processes (think of parts that are floppy (i.e. plastic bags, or bags of chips), or parts that are complex shapes and can get tangled together/interlocked, or food products that are soft or jelly-like, etc.)

With robotics, the secret is:  Don’t try to do it all at once like a person does.  Break it down.

Take bin-picking as an example.  A lot of people try to solve it straight-up, the same way a person does.  Sometimes you can, with basic parts.  But sometimes you can’t because of the complexity of the parts. 

A person looks at the bin and, in a split second, decides which part makes most sense to pickup.  An automation system can solve the same problem by breaking the process down into a series of manageable steps.

Step #1:  Get part out of bin – Keep it simple, use brute-force when you can!

• Dump the bin of parts?
• If they’re metal, use a magnet to grab a bunch at a time?
• Use a bowlfeeder to feed them?

Step #2:  Get part singulated – How can I get them separated so I can grab just one?

• Drop them onto a table where they’ll sit flat?
• Set them on a vibratory table where you can get some separation?
• Use a series of belts of increasing speed to create gaps between parts?

Step #3:  Get part located – Accurately locate the one I want

• Use hard tooling to get individual parts into a known location?
• Use simple vision to locate the part in 2D space and pick it up?

You’ve now solved the application with simple technology.  Don’t get me wrong, there’s a place for 3D vision-guided robots and force-feedback systems and sometimes they make the most sense.  BUT, sometimes a series of brute force, simple steps is a beautiful thing!

I’m often surprised how much time up front is spent talking about the nuts and bolts and specifications of the equipment being purchased, and how little time is spent really defining what success looks like.  The equipment (automation, robots, PLC’s, conveyors, whatever) are all just means to achieve a business outcome.  At the end of the day, what you really care about are reduced production costs, higher product quality, or greater production capacity.

That is what should be measured, that is what an integrator should be held accountable to.  Define the contract such that the integrator needs to deliver this – regardless of the bits and bytes of what they put into it.  If they missed or under estimated something – it’s their responsibility to do what needs to be done to achieve the business outcome that was agreed upon – period.

OEE (Overall Equipment Effectiveness) is a quantitative method used measure performance and takes into account the three major things in an automation system #1 How fast does it run, #2 The system uptime, and #3 The product quality coming out of it.

Here’s how you calculate it.

OEE = Performance Efficiency * Availability * Yield

Performance Efficiency = How fast does it run

Example – the system is designed to run 100 pieces per minute, the final system as it is installed runs 98 pieces per minute.

PE = 98 ppm/100 ppm * 100% = 98%

Availability = How much time the system runs of the total available time (uptime)

Example – In a week’s worth of production, over 2 shifts (4800 available minutes), the system has 5 minutes of downtime and 20 minutes of changeover.

Availability = (4800 minutes – 5 minutes – 40 minutes) /4800 minutes * 100 % = 99.06%

Yield = Percentage of good widgets made (quality)

Example – 2 defective pieces out of 1000 pieces made

Yield = (1000 pieces – 2 pieces)/1000 pieces * 100% = 99.8%

OEE = PE * Availability * Yield

OEE = 98% * 99.06% * 99.8% = 96.9%

Figure this out up front.  Work with the integrator to agree on what this number needs to be.  Agree on the inputs that are required to achieve this (i.e. the system needs to have good product going into it, if it is going to have good product coming out).   Spending the extra time up front to define and agree on this metric will ensure you get what you really want at the end of the project.

In some upcoming blog posts, I’ll walk through some examples of how to put this together.

I get asked this all the time.  Rough numbers, what does a robot cell cost?  What’s the total cost of ownership?  How do you justify it?  What is the return-on-investment (ROI)?  What is the internal-rate-of-return (IRR)?

Here’s my rules-of-thumb.

Companies automate for a combination of the following 3 reasons:

Reason #1:  To Save Money:

Labor savings is the most obvious reason.  Labor costs range greatly depending on the industry, geography, if it’s a unionized environment, etc.

Typically, labor costs per operator range from a low-end of $20k per year to a high-end of $80k (all-in costs including wages and benefits).  Besides direct labor savings, other benefits of automating often include improved quality, and reduced scrap and re-work.  These costs are often tougher to quantify, but can play a big role in certain applications.

Reason #2:  To Make More Money:

Often I see the existing production equipment either starved or bottle-necked because people aren’t fast enough to load or unload it.  In some cases, a manufacturer could sell more product if they had the capacity to make it.  By using robotics, you can run faster.  This increase in throughput (and revenue) comes at a low cost in relation to new production equipment.  In other instances, manufacturers are outsourcing the overflow production to meet demands.  By automating the loading and unloading, they reduce or eliminate the need to outsource (really back to reason #1).

Reason #3:  Because the Government Tells Them They Have To:

In most cases these are ergonomic issues – stresses and strains from high-speed, repetitive tasks or lifting of heavy objects.  They result in worksman’s compensation, lost time injuries, added rotations through strenuous jobs, etc.  Usually ergonomics doesn’t make or break the business decision to automate, but it can be an important factor.  From my experience, ergonomic costs can range from 5% and 20% of the direct labor costs.

Other times, the risks are more serious than stresses or strains.  Sometimes, the sole motivation is to get people out of hazardous jobs.  A robot is a lot easier to replace than a human life.

What Does a Robot Cell Cost?

A typical, single robot cell is $300k +/-50%.  Obviously, this is an order of magnitude estimate and will vary depending on the complexity of the process, but generally most single-robot systems will fall into this cost range.

This will include:

• Mid-sized Robot
• Robot End-Of-Arm-Tooling or Gripper
• Control panel including PLC, Operator Interface Screen (HMI), safety circuits, motor starters, etc.
• Cell guarding
• Customized engineering for your system to complete the desired process
• Some auxillary equipment – such as conveyors, deburring equipment, etc.
• Fabrication, assembly, setup, runoff at the integrator’s facility
• Shipping to your facility
• Rigging and installation
• Integratation with your existing equipment
• System specific operator and maintenance training

What About On-Going Costs?

Typical costs outside of the main purchase will include – spare parts, yearly service and maintenance, yearly replacement/wear items.

What is the Return-On-Investment (ROI)?

Anything between 12 months and 36 months is a no-brainer.  At a minimum, if you have 2+ shifts of operation and all-in labor costs of $35k per person, you’ve got a strong business case to look at automation.

Below is a link to a spreadsheet that outlines the typical business drivers and system costs.  You can use it as a tool to get a high-level understanding if robotic automation is a fit for you.  Enjoy!!

http://spreadsheets.google.com/ccc?key=0AqIbTF_Xcj00dHRWVVdJbTJ4ZHNaSkV3blFnZWNjY3c&hl=en