Robot Shift

I saw a commercial for the new Apple iPad .  In it they said “You already know how to use it”.  That really resonated with me.  That’s the way great automation systems are – the operators already know how to use them.

What makes them simple to use?  I may be getting pretty nitty gritty here, but it’s the way they are programmed.  Most people tend to think, and therefore program, based on a series of steps or sequences.  The problem is, when a robot gets to step 78 of a 123 step process and something out of the ordinary happens, it doesn’t know what to do next.  Think of how frustrating it is for you when your Windows computer locks up.  That’s the same feeling an operator gets on a daily basis with a glitchy automation system that runs on step or sequence based logic.  This ties into people’s perceptions, beliefs and acceptance of the equipment in your plant.

Great automation systems don’t follow a series of steps, they are programmed with rules or priorities.  These priorities allow the robot(s) to make decisions about what is the most important thing to do based on the state of the equipment within the cell.  This means it handles the the what-if situations that inevitably come up with ease.  This makes it simple and intuitive for an operator to:

• Recover after an E-Stop is pressed
• Recover after a power outage in the plant
• Recover when parts are out of sequence
• Recover when the process is stopped and parts removed
• Start up after a changeover
• Start up on a Monday morning

Not only does it handle these fault scenarios better, but it also runs better and makes more widgets.  Because the system has an understanding of the priorities, it can continually adapt its cycle to optimize the process to keep the highest priority equipment running at the highest capacity possible.

Every integrator is going to tell you that their systems are easy to operate, but how do you really know?  Ask them to talk you through the recovery procedures for the fault scenarios I’ve listed above.  Or ask to see their operator manuals and review these procedures.  Ask their references how they recover from these situations.  It shouldn’t take an operator more than 1 or 2 steps to get the system running after one of these occur.  If they have a 12-step procedure to recover – it’s too complicated.

“Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius — and a lot of courage — to move in the opposite direction”  – Einstein

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.

Industrial automation systems are a lot like coin sorting machines.  You dump your coins into the sorting machine and it uses simple rules (tooling) to separate and organize your coins into quarters, dimes, nickels and pennies.  Automation is the same.  Bowlfeeders, part crowding, sieves, robotic vision-guidance, etc. are all really just fancy ways of doing the same thing as a coin sorting machine.  They take random widgets and organize them using tools (hardware or software).  The key is they do it without thinking.

That’s really the question you need to ask yourself when looking at completely automating a process – “Can this process be broken down into a series of steps such that a set of rules can complete it without thinking?”

As much as we think automation and robots are “smart”,  they’re really not.  A robot can’t improvise or handle a new situation it was never designed or programmed to handle.  As technology marches forward, it continues to raise the bar higher and higher by providing more powerful tools, but the overall strategy remains the same.

This strategy means some processes can’t be automated, since they require a person to figure out the anomalies that inevitably come up.  But what if you could semi-automate them?  What if you could remove the laborious, time consuming, non-value added tasks and leave the people to do what they do best, the thinking part?

I’d like to see a new generation of safe, interactive robots that can work with people to perform these tasks. 

A good example where this could fit is putting a gas tank into a car on an automotive assembly line.  The majority of the process, moving the tank from the rack beside the line to the car, is time-consuming, simple and adds no-value to the car itself.  It’s the very final part, where the tank is actually mated with the car, that the person’s brain starts to get used.  That part, is always slightly different and requires thinking. The operator moves fuel lines and wire harnesses out of the way, jiggles the tank into place in order to get the bolts through the holes and threads started, and connects connectors and plugs by wiggling them into place.  It’s this part that makes the process too difficult to completely automated.

If you could introduce a safe, interactive robot into this scenario, the non-value added labor could be eliminated from the process.   A robot could automatically get the tank from the rack, bring it to the car, raise it close to the insertion point, and then track along with the moving car waiting for the operator to help it with the next steps.  An operator, who was working on another value-added task on the car, could then grab a hold of the gripper or the robot arm itself and move the robot and gas tank into place.  Just like two people who work together to lift a heavy object, the robot and person would work together to insert the gas tank.  The difference would be, in this case the robot does most of the lifting and the operator provides enough force to direct and guide it.  Safety scanners or safety mats could be used to determine when the robot and operator are in the same area, and would put the robot into “interactive-safe-mode”.  In this mode, the robot’s torque would be limited such that at the robot could not exert enough force to hurt someone.  The servo motors would provide just enough torque to hold the robot itself up, along with its load.  Any additional force input (from the operator) would be used to guide the robot.

There are other possibilities as well.  In traditional robotic cells, instead of teaching the robot with a pendant, the robot could moved into desired positions by manipulating the arm itself.  This would be easier and more intuitive for people with little robotic experience to work with.  Paths could be taught this way, allowing the operator to move the robot through its the sequence of operations and teach the path points along the way.  Even fault recovery could be easier.  Instead of having to jog a faulted robot out of a tight spot using the pendant (i.e. inside a CNC), the the operator could physically guide the robot arm out.

Currently, in the medical field robots are used to interact with and touch people.  They augment human performance making the doctor’s hand steady or more precise.  They do this in a safe manner such that the patient, doctor and nurses are not endangered.  If this technology exists today in the medical field, then why not apply it in an industrial setting?

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