This article discusses Scrum vs Kanban. Dynamic business environments and complex organizational structures induce change that possesses the ability to destabilize and frustrate even the most established business models. The key to a successful organization is the effective management of service delivery through efficient methods and practices. Efficient and smooth workflow practices are believed to be accomplished through Agile methodologies with an emphasis on flexibility and rigor to optimize utilization of resources. Two popular implementations of Agile are Scrum and Kanban. In would be fitting to compare and analyze these processes in an attempt to understand the dynamics behind their respective methodologies.
Scrum: This is an iterative and incremental process that aims to deliver marketable products or features upon the completion of a fixed duration iteration, called a “Sprint.” Scrum defines the scope within a Sprint and enables the optimization of resources through the formulation of cross-functional, self-organizing teams collaborating to enhance the scope of every subsequent Sprint. This process tool also enhances the predictability and learning based upon previous Sprints. Scrum upholds the cornerstones of transparency, inspection, and adaptability while breaking away from the rigid organizational structure with its predefined roles and responsibilities.
Kanban: This process propagates the implementation of visual process management, wherein immense importance is given to display the work in progress and resources are guided by production criteria like: (i) What to produce? (ii) How to produce? (iii) How much to produce? Kanban is a practice adapted by organizations to incorporate incremental and evolutionary change, which builds an efficient workflow through flexibility in assigning work priorities. By limiting work in progress (WIP), this method aims to expose, stimulate, and continuously improve the system. Kanban lays impetus on measuring to optimize the lead time, which is the average time taken to complete, also known as the “cycle time.”
Similarities between Scrum and Kanban
Both Scrum and Kanban are process tools aimed at optimizing the workflow practices and appear to be very similar in approach. They are sometimes easily confused to be one and the same. The following similarities lead to the confusion:
- These are both empirical in their approach as every project or process is unique and requires improvisation that yields the desired results by effective implementation of these tools.
- Scrum and Kanban are both implementations of Agile, packaged to formulate workflow process tools.
- Both Scrum and Kanban use pull scheduling to optimize allocation and utilization of resources.
- Concept of limiting the WIP: Both Scrum and Kanban limit the “work in process” by restricting the WIP within a Sprint and work cycle, respectively.
- Both Scrum and Kanban are aimed at process improvements to yield optimized workflow through the Lean methodology to yield enhanced velocity and reduction in lead time, respectively.
- Both Scrum and Kanban focus on splitting the project or process into smaller and manageable independent work cycles that are capable of delivering releasable products or features.
In addition, it is believed that these two approaches are compatible and can indeed be mixed to derive the benefits of both these methods. Some people even go to the extent to promote a concept called Scrumban, while others are a little wary of mixing them up and recommend practicing them as two distinct approaches.
Differences between Kanban and Scrum
Both Scrum and Kanban may appear to be similar, yet these are inherently distinct approaches that have evolved to attain a refined state that yields efficient workflow practices.
The following are the key differentiators that distinctively define Scrum and Kanban:
- Scrum breaks away from the stereotype roles and structure of a conventional organization to formulate self-organizing, cross-functional teams. On the contrary, Kanban does not necessarily prescribe cross-functional team structure and can also find implementation within the existing organizational structure.
- Scrum prescribes the roles of Product Owner, Scrum Master, and Development Team, whereas Kanban does not prescribe any specific roles and can adopt the existing roles of a specialist structure.
- Scrum prescribes fixed length iterations called Sprints, whereas Kanban does not mandate fixed duration iterations. Rather, Kanban encourages optimization of the work-cycle through reduction in lead time and enhancement of the velocity of workflow to achieve more through multiple cycles that optimize the workflow.
- Scrum recommends numerous rules and thus comes out to be more prescriptive. Kanban, however is more open, flexible, and adaptive, making it less prescriptive in nature.
- Scrum restricts change within a Sprint and seeks a specific amount of work commitment within iterations. Kanban, on the contrary, is open to change within iterations while operating within the prescribed limits.
- Although both Scrum and Kanban limit the WIP, they adapt different means to restrict the work in process. Scrum focuses upon containing the WIP within a Sprint, whereas Kanban limits WIP per workflow state.
A holistic analysis of the similarities and differences between Scrum and Kanban validates that although these appear to be visibly distinct approaches, they also draw out multiple similarities. This empowers the organization to select the best suited method and also enables them to refine and customize their approach.
Suitability of Kanban vs. Scrum
The suitability of Kanban over Scrum, or vice versa, should logically entail an analysis based upon the business environment and prerequisits required to establish efficient workflow practices. There are specific conditions that tilt the balance in favor of one or the other, as discussed below.
Conditions with resultant Kanban recommendation over Scrum:
- The requirement to instantly implement efficient workflow practices without disrupting the existing structure of roles and responsibilities advocates for Kanban.
- The need for a less prescriptive method or tool promotes Kanban.
- Long and continuous flow of process deliverables tilt the preference towards Kanban.
- It is recommended wherein the Lead time is the key parameter to drive efficiency.
- If fixed length iterations are not suitable, Kanban is better suited compared to Scrum.
On the contrary, Scrum implementation may be recommended based upon certain parameters, like the need to have fixed length iterations for better control and instances with a requirement of standardized output driven through, a process guided by rules, which are prescriptive in nature. The requirement of cross functional teams to establish teams that are independent of hierarchy promotes Scrum over Kanban.
The suitability of Kanban over Scrum or vice versa is driven by the inherent strengths and weaknesses of these tools based on the nature of the project or processes that operate through independent and self-controlling teams. Thus the limitation of one tool propagates the implementation of the other.
How to Choose Which Process to Use: Kanban or Scrum?
Both Kanban and Scrum are evolved methodologies that have a specified application in different scenarios. It is important to understand their applicability to recommend the best option and to deduce the best fit on a case-by-case basis.
However, it is believed that Kanban is a refinement over Scrum and that it finds higher applicability across software development projects.
It could be beneficial to draw some techniques and characteristics of Scrum and implement these with a few taken from the Kanban methodology as well. Inherently, both of these methodologies are derived from the Agile concept and principles. It is empirical to differentiate the applicability based upon an understanding of which method best justifies the Agile principles in a given scenario. Thus the loyalty towards Agile principles renders the best fit.
Both these methodologies are genuine extensions and implementation of Agile. Yet the actual question still remains unanswered. Is it logical to keep expanding upon tools and methods to create customized tools that are limited to scenarios? On the other hand, it could be practical to keep improvising based upon a basic method to evolve and customize the tool as per requirement. Thus it might not really be required to establish a new tool every time we are faced with constrains. Existing and established methods, such as Scrum, XP, Crystal, and now Kanban, should suffice for some time into the future.