ULTRAMAX-Advanced Process Management



ULTRAMAX® 7.0

© 2004-6, Ultramax Corporation, Cincinnati, Ohio, USA.  All rights reserved.

carlos.moreno@ultramax.com

UMAX70.doc 4/16/06

Introduction:

These are the major developments to help problem detection (e.g., process incapabilities, process upsets), to simplify installation and maintenance, and to increase speed of optimization.  The ULTRAMAX Method is now positioned as Advanced Process Management (APM) to compare it with Advanced Process Control (APC) (both multivariable).  There is a patent pending.

  • The new “Capability/Consistency Analysis” is used both for the up-front Baseline Capability Analysis; and for detection of specific problems and periodic auditing of process capabilities to satisfy business requirements (much more than just quality issues). [detection]

The Baseline Capability Analysis is a valuable tool even for customers not interested in optimization. 

Note that the Baseline Capability Analysis itself does not contribute to the effectiveness of Sequential Empirical Optimization (SEO); the test is done for the customer to understand the issues of process capabilities independently of the issues of applying SEO.  Also, passing this test is a requirement for UMC to issue performance guarantees. 

  • Data Validation: In case of failing new sequential data validation, help plant personnel by indicating which variables are most likely to be the source of the problem, so as to be able to determine the cause and correct the situation for the future (basic Quality Control procedures).   [detection]
  • Simplify restarting a round of Sequential Empirical Optimization (SEO).   This has been an important thrust of product development for version 7.0 .  [simplification]
  • No longer use Prior Region.  This feature makes starting and maintaining an Optimization Plan much simpler.  [simplification]
  • Automatic Scenario Management. This feature enables representing various components which may or may not be operating at any one time in one ULTRAMAX application file, rather that having to design and maintain one application file for each scenario.  A scenario is a different combination of operating process components.  [simplification]
  • Elimination of application size limitation.  This is particularly valuable to be able to recall process behavior and optima for earlier combinations of uncontrolled inputs, and thus avoiding having to re-learn and “climb the mountain” under those conditions again.  Also there is no code limit to the number of inputs or outputs.   [simplification, performance]
  • Adjustable ALARM threshold values.  For users to select the sensitivity of the Alerts (ALARM, Warning, Note) for each application (product / process), which affects messages and turning Closed-Loop off.
  • Optimization Management Screen (OMS) at the optimization workstation: Simplify integration (automatic data exchange with the DCS) by automatically providing an operator interface before or instead the end-user installing the OMS directly in the control room consoles.  [simplification]
  • Calculations:  Do not require the customer to have Fortran, or having to use it.  [simplification]
  • Transient Optimization: Optimize without waiting for the transients due to readjustments to fade away, useful for uncontrolled inputs that change a lot (e.g., load-following boilers).  [performance]
  • Profile Modulation:  Speed up optimization when it is known that variable values should follow certain patterns.  [performance]
  • 7.0 is available for WinXP, Win2000 and NT4.0
  • Implementation services for 7.0 now include much more thorough management involvement and follow-through support for the application.  This, together with the simplification steps, was done to avoid the following frequent syndrome.  Once getting great paybacks if a few months, ULTRAMAX fell into disuse after a few years – frequently associated with major changes in the process and with changes in plant personnel. 

 

Description of new features:

1.     Up-front Baseline Capability Analysis: The analysis is the new Capability Analysis with regular production data at baseline adjustments before running ULTRAMAX.  This analysis is much more thorough and discriminating than anything available before.

2.     Capability / Consistency Analysis:  This is a new analysis that can be done with the Baseline data, with regular SEO data, or with any operating data. 

The report analyzes:

·       Whether constraints were being satisfied by the data, and will be satisfied in the future by the estimated distributions. 

If constraints are satisfied, then operating improvements are to improve the Scorecard; else improvements are to learn first how to regularly satisfy constraints.

·       Any loss in output “effective operating ranges” to provide safety against constraint violations; which may reduce the ability to get more desirable Scorecard values.  The loss should be approved by the end-user.

·       In the extreme of the above, whether the effective operating range is positive for all outputs with upper and lower constraints; else the process is totally incapable.   Further, the effective operating range needs to be larger than 3 sigmas for SEO to be effective.  

·       How close to the optimum (in the effective operating range) SEO can quickly take the process.  The loss should be approved by the end-user.

Until the last three issues are resolved, the process is not sufficiently capable.  To resolve the issues it will be necessary to modify the Optimization Plan and/or to reduce noise – that is, be able to explain variations in outputs better.

The Capability report with baseline data is mostly for the benefit of customer’s clarity and perception; and in particular to understand process capabilities before doing SEO.  Neither collecting baseline production data for the analysis, nor the report itself, is necessary to obtain gains with SEO (if the process is capable).  However, with the Baseline Capability Analysis it will be simpler to evaluate gains – which is desirable for most new customers.  The baseline capability analysis report values could be reproduced with other standard statistical packages.

3.     Data Validation.  When entering new data and doing a What-if, the Advice Report displays a new column named “Deviation”.   This Deviation indicates, variable by variable, where each value stands in terms of the distribution past data, in order to detect which variables may be most different from past ranges – and thus possibly indicate a problem.  This logic applies equally to inputs and outputs. 

Note that it is possible to have all individual deviations small and still have a large multivariate deviation index, which is a case of having an unusual combination of variables.

4.     Simplify restarting a round of Sequential Empirical Optimization (SEO)

This feature raises the adaptability and flexibility of ULTRAMAX a significant notch, leaving further behind model-based solutions (that would require off-line rebuilding of prediction models – whether first-principle or Neural Network based).  This feature will also reduce the instances of people not re-starting ULTRAMAX -- after significant changes with the process ‑‑ because of the relatively higher complexities involved in the old method. 

Background: An important aspect of the ULTRAMAX® solution to optimize operations is the quick, dynamic adaptation to changes in:

1.      the process (e.g., new type of burners, a new duct, new mixer, etc.)

2.      discovering new variables to be included in the Optimization Plan (e.g., include a new input to reduce noise; a new quality characteristic)

These kinds of changes result in the stored run data no longer being complete or no longer being valid (i.e., no longer representing how the process will perform).  In such cases one starts a new “round” of SEO, basing optimization on a new set of now valid data.  Continuous improvements with ULTRAMAX calls for this situation to happen with some regularity. 

Historically, several customers have ceased to continue regular use of ULTRAMAX; partially because of:

a.      the perceived difficulty or uncertainty in re-starting a new round of SEO -- especially when the customer continues on their own without requesting help from the Agent or Ultramax Corporation (UMC) personnel; coupled with

b.      the belief that they can re-optimize performance based on personnel experience.

The table below describes the new simplifications in starting a new round of SEO; possible because of the new features “No Prior Region” and “Automatic Scenario Management” explained below: 

Old procedures (up to 6.0)

New procedures (7.0)

·        Ignore old invalid or incomplete data.

·        (if any) add/delete variables; update global factors (economic factors, requirements) and calculations

If multiple scenarios, do both tasks above in each of the scenarios’ application files.

Same, except that even in the case of multiple scenarios, it is done in only one application file. 

Set Prior Regions around current best known adjustments. 

If multiple scenarios, do it in each of the scenarios’ application files.

No longer done

And then continue operating -- as one would even without using SEO -- with the current best known adjustments, ready to obtain available benefits through refining adjustments.

5.     No longer use the Prior Region

The equivalent function is now defined by the first run data entered into (a new round of) SEO and by the MIDs in the Optimization Plan.  The first run is the currently best known process adjustments.   The definition of the input MID is now changed (see below), roughly three times the value with the previous definition. 

Eliminating the Prior Region has two mayor benefits:

·       Simplifying the formulation of the Optimization Plan

It also makes the application impervious to errors in the definition of the Prior Region, as has happened with some frequency in the past.  The input MIDs need to be determined a little more carefully, though.

·       Enables faster improvements (and more boldness) in the earlier cycles of Sequential Empirical Optimization (SEO)

6.     Automatic Scenario Management

This feature enables representing various components which may or may not be operating at any one time from one ULTRAMAX application file; that is, with one Optimization Plan (conceptual model), one set of run data. 

Alternate operating components may be: physical modules (burners, filters, nozzles); raw material used (including alternate suppliers); supporting material used (fuels, cooling fluids, tool bit alloys); procedures (cooling or not); etc.  Each possible combination of operating components is called a “Scenario”.   This represents uncontrolled inputs without the traditional “gradual” requirement.

The benefits of managing all scenarios from one application file is to provide much more flexibility and simplicity (set up, automatic starting of a new scenario, restart SEO and maintenance), plus faster overall optimization. 

Previously, each scenario required its own application file (as many as 60 in one case), with the Optimization Plan with its particular operating variables and Prior Regions; all of which represented significant overhead and care.  Also, general changes such as including new variables and changing the values of the Global Factors to represent current management priorities and economic factors, is now made only once, in only one application file.   

A rewarding aspect of this simplification includes not having to decide up front which scenarios will be used in the future. 

Three new elements enable this simplification:

  1. Component Inputs:  This is a new type of variable, with the values of 1 if the component is operating or 0 if not operating.

Component inputs are uncontrolled inputs (role 2) – i.e., with values determined externally to ULTRAMAX[1]. 

  1. Dependency field:   This is a new field in the Optimization Plan.  The Dependency Field is either blank or has the name of a component input. 

The Dependency Field can be used both on inputs and outputs.

If the dependency field is undefined or blank then the variable is always operational (the most common case, and as it happens when uploading older ULTRAMAX application files).  If the dependency field is defined, then see next.

  1. Conditional Variable: If the dependency field is defined then variable acts as a conditional variable, with values only when its “component variable” is operating (has the value of 1); and with undefined value otherwise (has the value -777). 

In addition, applications with component inputs optimize faster because they are able to extrapolate information from similar scenarios, particularly valuable before much data is collected.

7.     Elimination of application size limitation.  There are no longer limits in the application size (# inputs, # outputs, # run data). 

This feature yields three main benefits:

A.    Keep older historical data to know how the process behaved for older experiences of combinations of uncontrolled inputs – resulting in faster optimization when those combinations are (almost) repeated. 

B.    Keep old run data that is no longer valid or complete for eventual plotting and analysis (rather than automatically loosing older data that exceeded the available size)

C.    Avoid the trouble of the customer having to get a larger version of ULTRAMAX when wanting to overcome size limitations

As far as the code is concerned ULTRAMAX can work for any number of inputs; however actual experience has been for at most 55 inputs.  There have never been any practical barriers to the number of outputs.

There is a limit to size based on the computer itself.  We have not experienced these limits because most computers today have ample capabilities.  At present the following requirements seems adequate for about 40 inputs, 60 outputs and 5000 stored run-data sets: 500 Mb ram, 3GHz, 250Mb available in the hard disk.  Each application of this size will takes less than 20 Mb of hard disk.

8.     Adjustable Thresholds of Alert levels.   The threshold values of alerts to trigger a Note, to Warning to ALARM is now adjustable by the user, as part of the ULTRAMAX Parameter values (see Blue Book).  This enables the user to select the sensitivity or frequency of the Alerts (and associated risks) given the actual behavior of the process.  As problems are solved and the process becomes more reliable (Quality Control), the user can tighten the thresholds. 

9.     Integration; Optimization Management Screen (OMS)[2]:

Integration is the automatic data exchange with the digital control systems (one way or bi-directional):

·       There is a new automatic OMS supported at the optimization workstation monitor. 

The benefit is to simplify integration by automatically providing an operator interface before or in addition to the end-user installing an OMS – of their design -- directly in the control room consoles.

Among various functions, the optimization workstation OMS displays current data, run-average data, the adjustment advice provided by the SEO technology, and the operator desired next adjustments.  There are buttons to:

Ø     Make the adjustments (the whole set of control inputs in a predefined time profile)

Ø     Choose among three operating modes:

o      Manual Supervisory Control: where the operator adjusts setpoints, biases, etc. as he/she would in the console but in a central location, without the aid of SEO.  This is very useful to develop practice and confidence that the integration installation and data collection procedures are correct; and also to collect Baseline operations data.

o      Advisory Optimization: where the operator has to approve each new adjustment advised by SEO.  The operator presses a button to implement the Advice or a revision typed in by the operator. 

o      Closed-Loop optimization: where the Advice is implemented automatically.  Closed-loop reverts to Advisory automatically when the SEO detects an upset or when the operator turns it off.

·       Integration now supports OPC communications protocol in addition to DDE.  OPC is more robust and reliable that DDE.  Other special needs can be satisfied as well by our integration supplier (at extra cost).

·       The variable definitions in the configuration of the Ultramax Even Driver (UED) is now updated automatically from the Optimization Plan.  This reduces the work and the chances for errors when changing the Optimization Plan.  The tags, of course, have to be defined and maintained by the end-user.  

Note, as well, that we no longer refer to the Character User Interface (CUI) version of ULTRAMAX. 

10. Calculations: Simple calculations are, as before, provided by the GUI.  More complex calculations are now provided through DLLs (vs. direct linking).  Ultramax Corporation (UMC) or the Agent can provide the DLL. 

11. Transient Optimization:  With Transient Optimization data collection does not have to wait to achieve some sort of operating steady state.  Data collection starts immediately after an adjustment. 

One immediate result is faster optimization. 

Transient Optimization requires new variables to represent past behavior and which affect current transient performance.  This reduces noise and thus enables higher potential improvements.

One of the effects of having transient technology is to recognize that optimal adjustments are different whether some uncontrolled input value is increasing as compared to decreasing.

Cycle times (time between adjustment) is restricted to be larger than the half-time of the transients.

12. Profile Modulation:  Profile Modulation is a mechanism to adjust similar inputs that are next to each other (such as temperatures, dampers, etc.) and to apply plant personnel knowledge that the adjustments should change gradually from one location to the next.  Based on this knowledge, optimization can be approached much faster than optimizing the inputs as independent physical adjustments.

Profiles can be defined in one dimension (like temperatures in an injection molding nozzle), in two dimensions (like damper openings in an array of burners in a boiler), and higher. 

The set of physical adjustments across the different locations is called a “profile”, and the profile is determined by a few parameters, many fewer than the number of physical adjustments.  Optimization decisions (virtual adjustments) are made on the parameter values, while ULTRAMAX also displays the corresponding values of the physical adjustments. 

Examples of parameters might be: average, slope, curvature, etc., or any other devised by the user.  This method could be used, for instance, to assure some sort of symmetry. 

The profile parameters appear as control inputs (role 1) (i.e., the decision variables) in the Optimization Plan, while the physical adjustments are ruled inputs (role 8).  Thus, optimizing the profile parameters provides improvements – while restricted to the geometry of the profiles -- much faster than optimizing the physical adjustments independently.  The time taken to approach optimal performance is about the ratio of number of parameters to number of physical adjustments. 

The number of parameters can be increased with time to represent more complex profile forms (e.g., like a Taylor expansion, more accurate with more terms) and eventually, when there is plenty of data, easily transition to adjusting each physical  position separately for ultimate optimization.

Example:

Optimizing the operations of a plastic injection molding machine includes optimizing the adjustment of temperatures in the nozzle.  This nozzle has one temperature control every three inches, nine in total. 

Standard approach

Take the adjustment of each of the nine temperature controls as a separate control input in the Optimization Plan. 

Profile Modulation approach

Experienced people believe (or know) that the temperature should change gradually in the nozzle from location to location. 

One simple profile representation is to assume that the temperature should follow a linear relationship along the location in the nozzle.  Such a profile can be defined by two parameters: average and slope (another possibility: first and last temperatures). 

With Profile Modulation the two parameters are control inputs (decision variables).  The nine physical adjusted temperatures are “ruled inputs”, calculated by the Profile Modulation.

The advantage of using Profile Modulation is to optimize faster (seven fewer independent control inputs), although being restricted to the linear relationship postulated by the user.  

Note that after optimizing the average and slope, it is easily possible to increase the flexibility of the profile.  E.g., we could add as a new control input a quadratic component -- which up to this time was zero -- to refine optimization further. 

There can be several Profiles in one Optimization Plan.

Profile Modulation, such as Integration and Transient Optimization, is available at an extra cost.

13. Minimum Important Difference (MID):  With the elimination of the Prior Region, the meaning and demands for the input MID has changed.  As in the past, the MID is often a somewhat fuzzy concept that does not have to be defined with much accuracy in order to optimize effectively.

The new summary of definitions is:

The MID for the Objective Function (Scorecard) is the minimum difference in value that managers consider important from a business point of view (same as before).

The MID for outputs with constraints are the maximum violation of constraints by individual data that is tolerable to management (same as before).  (Now it is also possible to enter MID=0 to represent a lack of any gray area around the constraint, e.g., a gray area due to errors in measurement.)

The two above indicate that ideally, for prediction reliability from a business point of view, the noise should be less than 1/3rd the output MID.

The MID for the control inputs are:

·       The MID defines the maximum change in adjustments considered acceptable from one optimization cycle to the next – typically to assure stability of process operations.  (In previous versions it was 3*MID)

·       Input MIDs should be sufficiently large such that they create an MID difference in outputs

The MID for uncontrolled inputs are the estimated total range of values.


 

 



[1]      More specifically, ULTRAMAX would not be a reliable tool to provide Advice on what component inputs to activate – which would violate the “gradual” Critical Success Factor.

[2]      Previously called the Operator Ultramax Interface (OUI)