The Theory of Constraints (TOC) is a management philosophy and methodology developed by Eliyahu M. Goldratt. It focuses on improving organizational performance by identifying and addressing constraints, which are bottlenecks or limiting factors that impede the system's ability to achieve its goals. The theory suggests that by managing and optimizing these constraints, organizations can enhance their overall efficiency and effectiveness. TOC emphasizes the importance of continuous improvement, system thinking, and the alignment of resources to exploit and elevate constraints to maximize throughput and achieve desired outcomes.
I have personally found that applying Goldratt's Theory of Constraint (TOC) and thinking processes to software development to be a highly effective in helping teams and organizations be more productive or just reduce tensions.
When I was in college I remember being required to read Goldratt's novel The Goal, and not connecting with the material. It was a somewhat interesting story, but my professor kept saying, "Abolish the local optima". This did not resonate with me.
Many years later I came across The Phoenix Project, which is a novel about DevOps based on the Theory of Constraint. After being impressed with that novel and being reminded of The Goal, I went back and read it. This time I had years of experience to relate to the story and it was like lightening struck. The concepts in the novel explained so many successes and failures I had experienced and provided a toolkit for how I could be better as a leader.
I'm still learning how to apply this toolkit, but it is too valuable to not share what I have learned.
TOC Applied to Software Development
One of the fundamental tools in the Theory of Constraints (TOC) are Goldratt's 5 focusing steps, known as the Process of On-Going Improvement (POOGI). Below are the 5 steps relative to software development as well as some concepts to keep in mind when applying TOC.
Identify the constraint: Determine the primary bottleneck or constraint in the software development process. It could be a specific team, a particular skill set, a limited resource, or a step in the workflow that slows down the overall progress.
Exploit the constraint: Once the constraint is identified, focus on maximizing the utilization of that constraint by ensuring it is fully utilized at all times. Allocate the necessary resources, skills, and tools to the constraint to prevent any idle time or wasted capacity.
Subordinate non-constraints: Align the work of non-constraints, such as other teams or processes, to support and synchronize with the constraint. Ensure they are providing the necessary inputs and outputs in a timely manner to avoid creating additional bottlenecks.
Elevate the constraint: Invest in actions or changes that can remove or alleviate the identified constraint. This could involve improving skills, acquiring additional resources, optimizing tools and technology, or restructuring the workflow to reduce dependency on the constraint.
Repeat the process: As one constraint is resolved, it is likely that another bottleneck will emerge. Continuously monitor the system and repeat the process of identifying, exploiting, and elevating constraints to achieve ongoing improvements.
As you are applying the five focusing steps of POOGI, you will want to continuously apply the following:
Measure and manage throughput: Focus on measuring and optimizing the throughput of the entire software development process rather than individual components. By tracking and improving the rate at which valuable software features are delivered, the overall system performance can be enhanced.
Abolish the local optima: Remember that the outcome of working deployed code is the objective and not making sure all the individuals on the team is fully utilized. Promoting individual productivity without considering bottlenecks in your flow can have negative effects to the overall flow and reduce the teams output of working deployed code.
Embrace continuous improvement: Apply the principles of TOC alongside other agile and lean methodologies to foster a culture of continuous improvement. Encourage experimentation, collaboration, and feedback loops to drive ongoing enhancements and adaptability within the software development process.
By applying the theory of constraints in software development, organizations can streamline workflows, reduce bottlenecks, and improve overall efficiency, resulting in faster delivery of high-quality software products.
Common Constraints in Software Development
While every organization is different, there are several common constraints related to software development. Below are some of the common constraints encountered:
Limited availability of skilled resources: The availability of skilled developers, designers, testers, and other technical personnel can be a constraint, especially when there is a shortage of expertise in specific programming languages, frameworks, or technologies.
Time constraints: Time limitations are a significant constraint in software development. Projects often have tight deadlines or specific release dates that need to be met, which can put pressure on the development team and impact the overall quality of the software.
Unclear or changing requirements: Ambiguous or constantly changing requirements can create constraints by causing confusion, rework, and delays in the development process. When the team is not clear about what needs to be built or if requirements keep shifting, it can affect productivity.
Dependencies on external systems or teams: When software development relies on external systems, APIs, or interactions with other teams or departments, any delays or constraints in those dependencies can impact the overall progress of the project.
Technical debt and legacy systems: Existing technical debt, such as poorly designed code, outdated technologies, or complex legacy systems, can act as a constraint, slowing down development, increasing the risk of errors, and making it difficult to introduce new features or improvements.
Inefficient or inadequate tools and infrastructure: The lack of suitable development tools, inadequate hardware resources, or slow infrastructure can become constraints, impeding productivity and hindering the performance of the development team.
Communication and collaboration challenges: Ineffective communication, misalignment between team members or stakeholders, or a lack of collaboration tools and practices can introduce constraints that hinder the progress of the software development process.
Quality and testing constraints: Insufficient testing resources, lack of automated testing frameworks, or challenges in ensuring the quality and reliability of the software can act as constraints, potentially leading to increased bugs, rework, and delays.
Identifying and addressing these constraints using the 5 focusing steps of POOGI and the other techniques Goldratt defines like Evaporating Cloud and Prerequisite Tree can help improve efficiency, optimize resources, and enhance the overall software development process.
Strategies to Address Constraints in Software Development
Below are some brief examples of applying the five focusing steps of POOGI to address some common constraints in software development:
Limited availability of skilled resources:
- Identify the constraint: The team identifies that the limited availability of skilled QA testers is a constraint affecting their productivity.
- Exploit the constraint: They ensure that the available QA testers are fully utilized by assigning them to critical testing tasks, helping them prioritize their work, and optimizing the testing process.
- Subordinate non-constraints: The development team aligns their work with the testing team, providing them with timely and high-quality code for testing.
- Elevate the constraint: The team invests in training programs to enhance the skills of existing QA testers and may explore hiring additional testers to alleviate the constraint.
- Identify the constraint: The team identifies that the development process is delayed due to a lack of efficient coordination and prioritization.
- Exploit the constraint: They focus on optimizing the development process by eliminating non-value-added activities, improving communication and coordination, and prioritizing critical features.
- Subordinate non-constraints: The team ensures that non-critical tasks are properly synchronized with the time constraint, reducing interruptions and delays.
- Elevate the constraint: They implement effective project management techniques, improve time estimation and planning, and streamline the workflow to reduce bottlenecks.
Unclear or changing requirements:
- Identify the constraint: The team recognizes that unclear or constantly changing requirements hinder progress and productivity.
- Exploit the constraint: They engage closely with stakeholders to clarify requirements, prioritize work based on available information, and seek prompt feedback.
- Subordinate non-constraints: The team aligns non-constraints, such as documentation and design, to support the evolving requirements and minimize rework.
- Elevate the constraint: They establish a robust requirement gathering and management process, emphasizing early and continuous collaboration with stakeholders.
Dependencies on external systems or teams:
- Identify the constraint: The team identifies that delays caused by dependencies on external systems or teams impact their progress.
- Exploit the constraint: They proactively communicate and collaborate with external teams to ensure timely delivery of required components or interfaces.
- Subordinate non-constraints: The team coordinates the work of non-constraints to align with the availability and delivery of external dependencies.
- Elevate the constraint: They establish efficient communication channels, improve integration processes, and explore options to reduce dependencies or enhance coordination with external systems or teams.
Technical debt and legacy systems:
- Identify the constraint: The team recognizes that technical debt and outdated legacy systems slow down development and impede flexibility.
- Exploit the constraint: They prioritize and allocate resources to address critical technical debt and streamline development processes.
- Subordinate non-constraints: The team implements practices like continuous integration, automated testing, and code refactoring to mitigate the impact of technical debt.
- Elevate the constraint: They invest in modernizing or replacing legacy systems, enhancing code quality, and allocating dedicated resources to reduce technical debt.
Remember, these examples showcase how the five focusing steps can be applied to common constraints, but each situation may require adaptation and customization based on the specific context and constraints faced by the software development team.
Outcomes of Applying TOC to Software Development
Applying the theory of constraints (TOC) to software development can lead to several positive outcomes and benefits. Here are some of them:
Improved productivity: By identifying and addressing constraints, the overall productivity of the software development process can be significantly enhanced. Optimizing workflows, eliminating bottlenecks, and streamlining activities can lead to faster and more efficient development cycles.
Faster time to market: TOC helps in identifying the critical constraints that affect the time it takes to deliver software projects. By exploiting, elevating, and subordinating constraints, organizations can reduce delays, improve time management, and achieve faster time to market.
Enhanced throughput: TOC focuses on maximizing the throughput of the entire software development system rather than optimizing individual components. By aligning resources, streamlining processes, and managing constraints effectively, organizations can increase the rate at which valuable software features are delivered.
Improved quality and reliability: By addressing constraints and optimizing the development process, organizations can allocate more time and resources to ensure better quality assurance and testing. This leads to improved software quality, fewer defects, and increased customer satisfaction.
Efficient resource utilization: TOC helps organizations make better decisions about resource allocation and utilization. By identifying constraints and aligning non-constraints to support them, resources can be optimized, and wasteful activities can be minimized, resulting in more efficient use of available resources.
Better project management: Applying TOC principles promotes a systematic and structured approach to project management. It encourages regular monitoring, measurement, and analysis of constraints and their impact on project performance. This enables proactive decision-making and effective project control.
Continuous improvement culture: TOC emphasizes the importance of ongoing improvement. By applying TOC principles alongside other agile and lean methodologies, organizations foster a culture of continuous learning, experimentation, and adaptation. This allows for ongoing enhancements and optimizations in the software development process.
Increased customer satisfaction: Through improved productivity, faster delivery, enhanced quality, and efficient resource utilization, the application of TOC in software development ultimately leads to increased customer satisfaction. Customers receive higher quality software products in a timely manner, meeting their expectations and requirements.
Overall, applying the theory of constraints to software development helps organizations optimize their processes, improve efficiency, and deliver software projects more effectively, resulting in positive outcomes for both the development team and the end-users.
Eli Goldratt on What is the Theory of Constraints? (05:13)
5 Focusing Steps cartoon (02:55)