Stottler Henke Associates, Inc.

Aurora/Aurora-CCPM™ Frequently Asked Questions

Table of Contents:

Reference Information:

Aurora-CCPM™ software combines a variety of scheduling techniques, intelligent conflict resolution, and decision support to provide the world's most advanced Multi-Project Critical Chain implementation.

Almost 20 years of R&D have gone into Aurora's development, mostly to meet many of NASA's toughest planning & scheduling challenges. Aurora's world-class capabilities resulted in it being chosen by Boeing fore the Critical Chain scheduling of the final assembly of the Boeing 787 Dreamliner consisting of over 10,000 tasks. Boeing now uses Aurora-CCPM for many projects both within their commercial business and also in their defense business.

The Aurora scheduling product history until 2005 is showcased in NASA's SBIR/STTR Hallmarks of Success, see: sbir.gsfc.nasa.gov/SBIR/video/stottlerhenke.html

What are Aurora-CCPM™ Hardware/Software Requirements?

OS/Hardware requirements:
Aurora-CCPM client and server can run under:

Nothing special is needed on the hardware side.

There are 32-bit and 64-bit versions of Aurora, 64-bit versions are for models too large for the memory limitations of 32-bit applications (circa 20,000 tasks with many resources per task). For speed Aurora runs in RAM so RAM requirements are dependent on the total number of tasks being modeled at one time.

Software requirements
Standalone and client/server version require Java. The server for the client/server version requires a webserver. We currently support and can provide complete installation instructions for Apache/Tomcat.

Database requirements when using Database option (SQL Server, Oracle, MySQL, etc.)
Aurora is not tied to any particular database, but requires an SQL compliant database. We can support SQL Server, Oracle, MySQL, and others.

What else about the infrastructure requirements or overall system architecture may be important/relevant.
Aurora is designed and implemented to be as flexible as possible. It can run standalone or as a WEB client, we have APIs to make it interface to other databases, etc. One can always save locally even when in the client/server configuration (unless you wanted this option turned off for some reason). Standalone seats can run without access to the internet. They can save files locally and then save them to the central database when net connected if desired (using the standalone version or the WEB version of Aurora). The WEB clients have the same option, they can always save to the central database or save local files. We are close to having a Mac version also, but since no clients have requested it we have not completed it.

Can Aurora be integrated with SAP?

Yes.  To date, Aurora has not been integrated with SAP, but it is built to integrate easily with third party applications.  In the case of SAP, we will work with one of our partners, Pipeline Software, to help with the integration.  See our partners page on our website. 

How can the different tasks (Names) in different systems be integrated? (mapping from legacy to Aurora)

Aurora creates a unique identifier for each new imported item.  In addition, there are available fields ready to map the names from the imported data into Aurora. Aurora also has a very extensive system for deploying custom fields, so if there are different names that need to be transferred across non-standard fields from the legacy system, they can be mapped to custom fields in Aurora.  If a user wished to retain the same task names for multiple projects that are being combined into one Aurora project, there is the option to affix a prefix with the file name of each of the imported project.  For example, if a task was called “build base” and three different projects have build base, it could be called “ship1_build base,” “ship2_build base,” and “ship3_build base.”

Explain planning and execution by task creation, dependencies, resource allocation and critical chain completion (Walk-thru with 10 or 15 tasks)

For a step by step example, see the Aurora CCPM basic template tutorial.  For a larger example, see this CCPM Demonstration video as well as other tutorials on the Aurora video tutorials page. Also refer to the following Index document accompanying the video, to see what occurs at different times during the demonstration video. 

The tutorials show the methods using the GUI. However, the Tabular editor could be used as one becomes more efficient in Aurora to help perform these operations more rapidly.

How does Aurora-CCPM handle re-planning (Add/modify delete tasks after baseline) without affecting the previous updates and how does it recalculates buffers?

Aurora does not make any changes to actuals (actual start date, actual end date, remaining duration) when performing a re-plan. The re-plan process eliminates all prior information about the critical chain and buffers; this information is then recalculated using the work that has not yet been completed. Note that this radical re-plan is only invoked upon user command; the more minor variability caused by adding or deleting small numbers of tasks is assumed to be covered by the buffering.

How does Aurora handle active task management and reports? (tasks in progress, to be started, etc.)

Aurora provides various graphical and textual reports to show tasks in process, tasks that are ready to begin, a prioritized task list, etc.. Graphical displays such as Gantt chart can also be customized with different color coding to the different stages of a project.  Much of this is demonstrated in the Detailed Aurora CCPM video on the Aurora video tutorials page.  Also see this Index document accompanying the video for an explanation of Aurora’s reporting capabilities, most of them recurring near the end of the video. Some screenshots of Aurora’s output reports are available on the screenshots page.

How does Aurora handle multi-project Critical Chain?

Aurora is based on a very sophisticated resource scheduling engine and provides much more in flexibility dealing with multi-project than other critical chain software. 
1. Aurora can use the drum buffer to stagger multi-projects, as is normally described in Critical Chain literature.
2. Aurora also has the ability to use the entire resource pool that will be used to schedule the multi-project critical chain projects.  Hence instead of using a drum buffer to stagger, users can potentially set different priorities to different projects, then let Aurora utilize the entire resource pool to stagger the different projects appropriately.  This method is shown in the following Multi Project critical chain video.

How is Slack in the critical chain caused due to feeding buffer handled?

Critical Chain is defined as the resource constrained critical path of the project network when using aggressive durations.  The goal here is to determine the critical chain before buffers are inserted. During the process where feeder buffers are inserted, some breaks are necessary in the critical chain to properly place the feeder buffers so that there is no initial impact on the feeder buffer.  In this manner, the critical chain is extended, and the total duration of the project may be affected.  However, the result is a proper and buffered critical chain project. 

Aurora provides an option to maintain the integrity of the initial critical chain even when the need arises for a feeder buffer impact or a feeder buffer incursion to occur before With Aurora’s built-in flexibility, an option can easily be provided if there is a  need for a feeder buffer impact or a feeder buffer incursion to occur before the project started so that the initial critical chain before inserting buffers is not moved.  However there are many examples that show that this changes the nature of  the critical chain execution processing, and may not be recommended for many applications. 

If the critical chain changes during execution, how does Aurora handle buffers, CC completion and task prioritization?

If a new critical chain is inserted or a new critical chain task is inserted, Aurora first checks how that affects the project buffer at that particular time.  For example, if one new item in the critical chain had to be added, Aurora will show how inserting that task affects the buffer situation and the Fever chart.  If the project was in the green up to that point on the Fever chart before inserting the new task, and then the Fever Chart was in the yellow after insertion, that would allow the project to proceed as is.  I.e., update only the project buffer, change the priorities of all the tasks appropriately and continue.

If the Project Buffer is way into to the red on the Fever Chart after new critical chain task(s) are inserted, then the original end date is no longer realistic, essentially we are working on a different project at this point. The incomplete remaining tasks (from the original situation plus the added task(s)) After new critical chain tasks were inserted, a new critical project schedule could be determined and then start executing and having new buffer impacts from that point, with a new determined end-date at the end of the newly determined Project Buffer.

How are tasks prioritized during execution in Aurora-CCPM?

Aurora uses standard buffering incursion from the Theory of Constraints Critical Chain to determine task prioritization.  Drawing on the concept of workability, a part of the standard critical chain theory, Aurora filters by whether a task is actually workable. Additionally, Aurora takes into account task priorities during initial planning of the critical chain schedules. They are not used extensively during execution, since buffer incursion will fully determine execution time rankings under normal circumstances; however, if two tasks have the exact same ranking due to buffer incursion the task priority can be used to break this tie.

How to handle date constraint? (like vendor delivery dates – Tasks not to start earlier than that)

In Aurora’s sophisticated scheduling engine, dates constraints are handled when the initial planning occurs. The schedule takes all constraints into account, such as “do not start earlier than a specific date”, the task will not schedule earlier than that, and the schedule developed will be as efficient as possible.

How are other constraints like (Start to Start, Finish to Finish) handled when using Critical Chain?

Aurora permits the use of a full range of constraints with critical chain.  It intelligently plans keeping all a constraints in force when buffers are inserted. 

Does Critical Chain require the use of finish-to-start constraints only?

No, Aurora can handle other types of constraints, besides finish to start, and still correctly plan and execute critical chain projects. 

How to identify near critical chains?

When Aurora determines the critical chain it calculates the sequence(s) of both precedence- and resource-dependent tasks that prevent the project from being completed in a shorter time, given the finite resources. 

Aurora includes a few methods for determining which one of the candidate critical chains should be considered the project's Critical Chain.  However, all the tasks that were candidate critical chain elements are so noted.  If one wanted to take this a step further, and determine activities that were within a certain tolerance of being on the critical chain, that would be something that could be added, but it would not be difficult as this type of information is already stored in Aurora. 

Can we maintain cost related info in Aurora?

Aurora includes a cost field for each activity, but this is a very basic property.  More sophisticated cost management and earned value management should be handled via a different software specifically designed for those purposes.

Resource constraint between tasks/resource contention: can it be viewed visually?

Yes, Aurora shows a resource-constrained relationship with a blue-grey line between tasks.

In this sample schedule, each task has a resource requirement attached as follows:

Task#
 Resources Needed
2
 1
4
 2
5
 2
6
 2

Note that there is a total amount of only 5 resources. Tasks 2, 4, and 5 are started at the same time (5 resources used). Task 2 completes, but there are not enough resources left to start Task 6, so Task 6 must wait until Task 5 is complete.

Example

Where is more information available per execution mode details?

Buffer management and updated priority lists, etc. may be a real-time or manual process. Actual rescheduling/re-planning is a manual process. This can be seen via the Project Manager Role during Execution (includes Audio) video on the page: http://www.stottherlenke.com/products/aurora/videos/

Job level status comments CAN be made so they are available to managers/supervisors in the task priority list. To see more detail about Critical Chain across the factory and across projects, see the Multi-project Critical Chain Demonstration video on the Aurora videos page.  Note that there is the link "Index to concepts presented with timestamps" below the video links. Also, the example is not maintenance specific.

Where is more information available per Buffer management?

See the Aurora videos page, and look for the Detailed Aurora-CCPM Critical Chain Video. There is discussion regarding scheduling with safe durations starting at about 8:25 into the video. (For more references, see the Index to concepts presented with timestamps link)

If you don't want to watch all the details from this point on, you can see the aggressive/CCPM scheduling at about 14:50 into the video, and at 16:30 there is a segment on the Comparison of Safe & Aggressive Durations.

Where is more information available per Resource management?

Human and facility resources, including physical space resources, can be addressed in Aurora/Aurora-CCPM. In the Detailed Aurora-CCPM Critical Chain video on the Aurora videos page, there is a discussion of some of the resource options starting 1 minute into the video. You can also skip to 10:40 and see the section on Analysis examples-show resource contentions graphically.

Also on the Aurora videos page, there is the Overview of Aurora (includes Audio) video, that uses an illustration from the shipping industry. It includes discussions of resources and resource sets starting at about 2:10 into the video. Much more detail is provided in follow-up videos provided on the same page. 

What size user base can be supported?

There is no upper limit of users that can be supported across various projects.  Read only access is unlimited. 

How to handle vendor payment based on task completion in Aurora?

Aurora provides flexibility so the client can determine the best way to support vendor payment based on task completion.  There are many options:
  1. Build the same way one did previously to implementing critical chain.  For example, if a client had a billing method based on the completion of tasks in Primavera, one could use this same task-completion methodology and report the project to Aurora, Aurora would interface back to Primavera with information on what has been completed, and billing would continue as normal.
  2. The ability to utilize the completion of major or all Critical Chain tasks.  E.g. if the vendor is billing based on Critical Chain, then the Critical Chain can be used on task-completions to bill all the feeder tasks intermittently between the last billing. 
  3. The last option is to be able to bill all tasks.  This may be a propos when there are long feeder chains that occur before the first critical chain task even occurs, so there may be extensive delays to payment if one used only critical chain tasks for payment purposes.
Therefore, Aurora’s goal is to provide the flexibility so the vendor payment based on task completion can be easily performed in any way the client wishes.

Aurora NAVY Application(s)?

Aurora is included in Parmalot, an intelligent acquisition and planning tool for upgrading U.S. Navy weapon systems. See this document (PDF) for more information.

Continuous Process Improvement (CPI)

CPI started as an OSD initiative focused on "continuous process improvement to maximize weapon system readiness while minimizing materiel flows and in-process inventories. The goal is to optimize reliability and cycle time while striking a reasonable balance with costs across the total life cycle value chain, employing:
MIT defines lean as "elimination of waste and efficient creation of enterprise value" and includes "optimization of value delivered to all stakeholders and enterprises in value chain. "According to the Lean Aerospace Initiative, "lean thinking is a dynamic, knowledge-driven, customer-focused process by which all individuals within an enterprise - indeed, the enterprise itself - continuously eliminate waste and expense, maximize resources and streamline operations, and create a total enterprise transformation endowed with added value. Lean tools and practices have been consistently shown to help target, identify, define, and implement improvements across a broad spectrum of enterprises."