Need for and Benefits of Additional Real-World Project Modeling Capabilities

Project management scheduling tools provide various capabilities for modeling and analyzing projects and/or a portfolio of projects. More specifically, these project management scheduling tools provide methods for modeling tasks, their relationships to each other (e.g., finish-to-start constraints), the resources that are available, assignment of resources to tasks, calendars for resources and tasks, and various other modeling capabilities. Moreover, these capabilities provide a great foundation for modeling many types of projects, and in many cases provide all the modeling capabilities necessary to execute the project successfully. However, there are many cases where without further real-world project modeling capabilities, the human project managers will be overwhelmed by the inaccuracies of the resulting schedule during execution since many real-world details are not taken into consideration. For example, NASA and others have benefited from hazard constraints, this constraint allows the modeling of hazardous activities in conjunction with the activities it is hazardous to, then during execution, hazardous activities will never occur simultaneously with any of the activities it is hazardous to. Without this constraint, the project manager would need to determine the order of activities during planning and put in finish-to-start constraints to control the ordering; however, during execution, if the ordering should be updated, the human scheduler would need to constantly check if the ordering should be updated to maximize throughput. 

Another real-world project modeling capability that is essential to project management scheduling is a preference constraint. Preference constraints are useful, are, at times, necessary to maximize project efficiency, and can have many different incarnations. For example, there are many cases where an activity may be associated with a specific organization, such as a shop, however, it is not absolutely necessary that the activity be performed by that organization. With this in mind, a preference constraint could be associated with activities that are preferred to be done with SHOPA, but if SHOPA is at capacity and SHOPB or SHOPC are not then the project management scheduling tool would schedule the activity in SHOPB or SHOPC, maximizing utilization and throughput while maintaining activities in their preferred shop as much as possible. 

Other types of modeling capabilities that are important include shift-based resource constraints. For example, there are situations where work should not be performed if it is likely to span more than one shift. Another shift-related case is for activities that do span multiple shifts, sometimes due to the nature of the activity they should be performed by some or all of the same human resources. There are other cases, some painting situations, where if it takes more than one shift to complete, different people can work on completing the activity. There are a plethora of other modeling capabilities that have been found to be useful/necessary to model and execute projects efficiently. 

Scheduling, at its most basic, is the process of assigning tasks to resources over time, with the goal of optimizing the result according to one or more objectives. Scheduling is heavily used in construction, manufacturing, defense, and service industries to minimize the time and cost associated with the completion or production of small to large, simple to complex projects. 

Beneficial Additional Modeling Capabilities 

This blog covers a diverse range of domains ranging from aerospace and manufacturing to pharmaceutical production and medical resident scheduling, demonstrating how better modeling leads to better outcomes and how generally applicable these modeling options are to most domains. These capabilities have been incorporated into the project management and intelligent scheduling tool, Aurora. Aurora is a software application used by NASA, and NASA has needed and now benefits from many of these capabilities.

The following bullet list provides an overview of modeling capabilities that have been found useful across one or more project/production domains.

• Ability to handle physical space constraints, including considering the creation and elimination of the space during the project. 
• Ability to model human resources with details beyond just an occupation, such as occupation plus a set of specializations and/or certifications. 
• Concurrent Constraints – Specify that two jobs need to happen at the same time in the schedule. 
• Exclusivities / non-concurrent constraints – Specify that a job cannot happen at the same time as another job or class of jobs. 
• Preferred Resources – Specify a preference order when defining a set of resources that are mostly interchangeable. 
• Alternative Resource Combinations – Specify different combinations of requirements that could be used to complete a task, including variants with different durations. 
• Ergonomic Constraints – Consider human physical limitations. For example, workers may have limitations on how long they can work on their knees, both in one sitting and throughout the whole shift. 
• Variable Duration Jobs – Specify that a job could use more people and get done more quickly, or fewer people and get done more slowly. 
• Special Manufacturing/Shift Control Properties – This is a set of properties that allows the user to control how jobs interact with shift breaks (can it go between shifts, can it go from one day to another, does it have to complete a certain length of time before a shift ends, etc.) 
• Capacity Change Constraints – This allows the user to specify a relationship between a task and a resource. Some tasks may make a resource available (e.g., adding a space zone that can subsequently be used for work), others may make a resource unavailable (e.g., installing panels that block access to a space zone). 
• Jig Support – This is specialized support that ensures that a jig is assigned to a series of work and will be retained throughout the work statement. 
• Tabular Editor – Most project management tools provide some kind of tabular view. Depending on the functionality this tabular view can be just a read-only view, or as we have found a powerful analytical tool and data transfer tool. By providing an Excelstyle view into the model and schedule data, the tabular editor allows the user to easily filter, analyze, extract, and enter data. Experience has shown that a “referenced paste” feature that effectively performs a VLookup cross-referencing incoming data with data in the Tabular Editor on key matching criteria provides a robust transfer data option without perfect row alignment.