Deep Dive Into Development: Understanding the Vertical Slice Methodology

September 23, 2023 - 10 min read

Wrike Team

In the world of software development, the vertical slice methodology is gaining recognition as an effective approach to building robust and user-friendly applications. In this article, we will take a closer look at what vertical slicing is, its key components, and the benefits it brings to development projects. We will also discuss the implementation steps, common challenges, and the impact of vertical slicing on project management. Finally, we will compare the vertical slice methodology with other development approaches to understand its unique advantages. So, let us dive deep and explore the world of vertical slicing.

The Vertical Slice Methodology

Vertical slicing, also known as vertical partitioning, is a development technique that focuses on delivering a fully functional piece of software that covers all layers of the application stack. Unlike traditional development approaches that build features incrementally, vertical slicing adopts a cross-functional approach to deliver end-to-end functionality in each iteration.

The concept behind vertical slicing is centered around delivering value to end-users early and frequently. Instead of working on isolated components or layers, the development team collaborates to implement a complete set of features spanning the entire stack. This holistic approach ensures that each release is a working software, providing users with tangible benefits from the very beginning.

Key Components

A vertical slice comprises several key components that contribute to its efficacy. These components include the user interface (UI), business logic, data access layer, and persistence. By focusing on all these aspects simultaneously, vertical slicing ensures that the end product is a fully functional entity that delivers value to end-users.

User interface (UI): Responsible for providing users with a seamless and intuitive experience. By focusing on the UI from the very beginning, development teams can ensure that the end product is visually appealing and easy to use.
Business logic: Encompasses the rules and processes that drive the functionality of the software. By implementing the business logic in each vertical slice, development teams can make sure that the end product is not only visually appealing but also provides the desired functionality.
Data access layer: Responsible for retrieving and storing data in the software. By including the data access layer in each vertical slice, development teams can see to it that the end product is capable of handling data effectively and efficiently.
Persistence: Refers to the software's ability to retain data even after it has been shut down. Including persistence in each vertical slice can guarantee that the end product is capable of storing and retrieving data reliably.

Employees meeting in a room — Photo by Christina on Unsplash

The Importance of Vertical Slicing in Development

Now that we have a clear understanding of what vertical slicing entails, let us explore why it is crucial in today's development landscape.

Enhancing Team Collaboration

Vertical slicing promotes collaboration among team members by breaking down silos and encouraging cross-functional work. With everyone working together on delivering a complete feature, communication flows seamlessly, and team members gain a holistic understanding of the software's intricacies.

This collaborative environment not only boosts productivity but also fosters a sense of ownership and shared responsibility within the team. When team members are actively involved in all stages of development, they become more invested in the success of the project. They can contribute their unique perspectives and expertise, leading to innovative solutions and better outcomes.

What's more, vertical slicing encourages knowledge sharing among team members. As they work on different parts of the software, they have the opportunity to learn from one another and expand their skill sets. This cross-pollination of ideas and skills strengthens the team as a whole and enhances their ability to tackle complex challenges.

Streamlining the Development Process

Vertical slicing brings greater clarity to the development process, where the team gains a comprehensive view of the software and can identify potential bottlenecks or issues early on.

This iterative approach allows for continuous refinement and adaptation, leading to a smoother and more efficient development cycle. As the team slices the software vertically, they can prioritize the most critical features and deliver value to stakeholders sooner. This incremental delivery not only reduces the risk of delays but also enables early feedback from users, which can inform future iterations and improvements.

Moreover, vertical slicing enables the team to manage dependencies more effectively. By breaking down the software into smaller, self-contained units, they can identify and address dependencies between different components. This proactive approach minimizes the chances of last-minute surprises and allows for a more predictable and manageable development process.

Lastly, vertical slicing facilitates better testing and quality assurance. With each slice representing a complete feature, the team can focus on thorough testing and validation, so that the software meets the desired standards and functionality. This attention to detail enhances the overall quality of the product and reduces the likelihood of post-release issues.

Workers collaborating in a room — Photo by Austin Distel on Unsplash

Implementing the Vertical Slice Methodology

Now that we grasp the significance of vertical slicing, let us dig into the practical steps involved in implementing this methodology.

Identify the core functionality: Start by identifying the essential features and functionality that form the backbone of your application. These should be prioritized based on their value to end-users.
Create a cross-functional team: Assemble a team comprising members with various skill sets, including UI/UX design, development, testing, and project management. This diverse team composition ensures that expertise from different domains contributes to the development process.
Define end-to-end user scenarios: Work collaboratively to define user scenarios that cover the entire scope of the application. This helps in designing and implementing the complete vertical slice of functionality.
Implement the full stack: Start by building the UI layer, gradually integrating the business logic, data access layer, and persistence. Each layer should be tested thoroughly to verify its seamless integration and functionality.
Obtain feedback and iterate: Once a vertical slice is completed, gather feedback from stakeholders and end-users. Adapt, refine, and iterate based on this feedback to continuously improve the software.

Common Challenges and Solutions

While implementing the vertical slice methodology, it is essential to be aware of some common challenges that teams might face. These challenges include managing dependencies between team members, ensuring effective communication, and maintaining consistency throughout the development process.

Managing dependencies between team members: This can be difficult when different individuals are working on different parts of the vertical slice. To overcome this, establish clear communication channels (e.g., daily stand-up meetings or virtual collaboration tools) so that everyone is aware of each other's progress and any dependencies that may arise.
Effective communication: Teams should prioritize open and transparent communication, so that all team members are aligned and have a shared understanding of the project goals and requirements. Regular meetings, such as sprint planning sessions or backlog refinement sessions, can facilitate effective communication and collaboration.
Maintaining consistency: Teams can achieve consistency by establishing coding standards, design guidelines, and documentation practices. Regular code reviews and pair programming sessions can also help identify and address any inconsistencies or deviations from established standards.

The Impact of Vertical Slicing on Project Management

Vertical slicing has a profound impact on project management, revolutionizing the way projects are executed and monitored.

Improving Project Visibility: With vertical slicing, project visibility is significantly enhanced. As each iteration delivers a fully functional feature, stakeholders and project managers gain tangible deliverables at regular intervals. This visibility enables them to make informed decisions, identify potential issues or risks, and adjust project priorities accordingly.
Facilitating Better Resource Allocation: Vertical slicing also facilitates better resource allocation. By breaking down the development process into cross-functional teams, organizations can ensure optimal utilization of resources. Each team focuses on delivering a vertical slice, enabling them to work independently while aligning their efforts with the overall project goals.

Comparing Vertical Slice Methodology with Other Development Approaches

Now, let us compare the vertical slice methodology with other commonly used development approaches to understand its unique advantages.

Horizontal Slicing: Also known as functional slicing, this methodology involves developing all the features at each layer of the stack before moving on to the next layer. While this approach provides a comprehensive view of each layer, it often leads to delayed feedback and a greater risk of integration issues. Vertical slicing, on the other hand, prioritizes end-to-end functionality, so that feedback is gathered early and frequently, leading to faster validation and increased reliability.
Agile Development: While vertical slicing shares similarities with agile development principles, it provides distinct advantages in terms of delivering functional software with each iteration. Agile development typically focuses on delivering user stories in smaller increments, but these increments may not always be fully functional. Vertical slicing, by incorporating end-to-end functionality, strengthens the agile development approach, resulting in a more efficient and customer-centric delivery cycle.

Dive Deep into Development with Wrike

Understanding the vertical slice methodology in development is like exploring the depths of the ocean. It allows you to delve deep into each feature, ensuring thorough development and testing. However, managing these slices across multiple features can be complex.

This is where Wrike comes in. Within Wrike, you can easily create folders for each feature or vertical slice. These folders can serve as a place where you can store development plans, testing results, and even your sprint retrospectives. This structured approach brings depth and thoroughness to your development process, much like exploring the depths of the ocean.

And when it comes to the other documents and workflows your business needs — whether it's sprint planning or bug tracking — Wrike has you covered with robust project management features and ready-to-use templates. Ready to dive deep into development? Start your free trial of Wrike today.

Note: This article was created with the assistance of an AI engine. It has been reviewed and revised by our team of experts to ensure accuracy and quality.

Wrike Team

Occasionally we write blog posts where multiple people contribute. Since our idea of having a gladiator arena where contributors would fight to the death to win total authorship wasn’t approved by HR, this was the compromise.

#Project Management Methodologies #Project Management Advice

Project Management 7 min read

5 Project Management Ideas that Should be Extinct

Project management has a wide spectrum of effective approaches. Everything from hands-off supervision to management by walking around... And then there are the ideas that should go the way of the dinosaur — disappear in a ball of flames. This is just a list of the top 5 PM ideas that should be extinct. And if they are still rearing their prehistoric heads in your organization, perhaps it's up to you to lay them to rest once and for all. Read on: 1. "Let's Manage the Project by Email" Everyone has heard at least one project manager say: "Email me a status report." This is the old-school method of requesting project status updates. Because according to this project manager, there is no better method for reporting on what's been done and where you're roadblocked. Which, of course, means that all comments from him or her will also be sent through email. And we all know how that ends: in back-and-forth communication that is 23 emails thick, with 7 buried attachments, lost in the noise and confusion of a cluttered inbox. "When did you send that updated slide deck again? What was the subject line? I can't find it. Can you resend?" The truth is there are better, more collaborative PM tools than email. In fact, it seems like a new one comes out almost every month. These tools transfer the bulk of your communication and status updates away from email and compile them into the PM tool, allowing projects to thrive outside the stranglehold of your inbox. Your action: Find a better PM tool than email. 2. "Let's Have Longer Meetings" There seems to be a prevalent idea in older generations that meetings are where the real work gets done. Ergo, longer meetings mean more work accomplished. And the more people in a meeting, the more everyone engages with what's happening in the project. Right? Um, no. David Allen, productivity guru and author of Getting Things Done, says that there are really only five reasons to have a meeting: 1. Give info 2. Get info 3. Produce options 4. Make decisions 5. Bask in the warmth of actual human contact (yay!) A large part of every successful meeting is everyone agreeing what the objective for the meeting is. And note that Allen didn't include reason #6: Waste people's time. The truth is, not everyone needs to be in a meeting. If someone's work is not directly affected by the agenda of a meeting, leave him to his work. Alternatively, if not everyone is needed for every discussion point, schedule the agenda so that you start with the majority of attendees and individuals can drop off once their portions are done. This motivates people to keep things short so everyone can get back to work. Also, meetings take time -- and time is your team's most precious resource. If it's spent going over details that could have been disseminated via email, or discussing items relevant to only one person in the room, then that's a waste of everyone's time. Schedule one-on-one consultations outside of meeting times, and use a collaboration tool to monitor the status of any task so there is less reporting being done face to face. Your action: Cut down the length of your meetings, and use a timer to enforce it! 3. "Let's Only Hire Local People to Work Onsite" You know it all too well, this bias toward hiring people who can come into the office everyday and work with you face-to-face. Admittedly, it does make the work routine easier if you can traipse on down to a cubicle and tell your team member what needs to be revised. But here's the question: what if the skills you need CAN'T be sourced in your immediate vicinity? And if you find someone who fits the job description, speaks your language, and can do the job but lives on the other side of the world, would you hesitate to hire him due to physical barriers? We're not in the 19th century anymore. There are advanced communication tools out there like Skype, Google Hangouts, and Facetime that allow you to chat with people remotely, with or without cameras. And once again, there are PM tools that live in the cloud, so collaboration and work can be done from any location with internet connectivity. The technology exists, so use it! Your action: Every time you recruit for a job, consider not requiring an onsite presence. Include the line "Remote work possible *for the right candidate.*" 4. "Let's Stick to the Plan, No Matter What" Have you ever worked under a project manager with no flexibility? It's a hell forged from the embers of micromanagement and the molten lava of ruthless dictatorship. To this kind of manager, the project plan is sacred and must be followed at all costs. Even when requirements change, team members disappear, or deadlines shift. Unfortunately for the uncompromising manager, life never works out the way we planned. Everything is in flux and project managers need to be flexible enough to juggle priorities and resources as needed. Otherwise, by sticking to a rigid plan, companies will deliver products that customers don't even want or need. Your action: Have a complete project plan, but be ready to change it up. Changes are not evil. They're challenges and opportunities to deliver better outcomes. 5. "Let's Describe Tasks Very Loosely and 'Wing It'" Are there still people like this, you ask? Yes. The ones who have vague project plans. The ones who send project briefs with only a title ("Please write an eBook for our email offer") or a general deliverable ("Create a new home page design") and never provide any details. The project is not properly kicked off, and the manager never actually formalizes their deliverable expectations. Team members are left wondering what reference material should be used, or what the business objectives are, because the project manager didn't bother to write a real project brief. Not giving a clear description of the output is just asking your team to be inefficient. Why not give them everything at the start, and then communicate with them what needs to be done before assigning it to them? Make sure you set expectations loud and clear. It boils down to efficiency and respect: give them everything they need to be efficient, and respect their time. Your action: Complete every project brief/task description and communicate with the team BEFORE the project starts! The way we all work is rapidly evolving. And in order to use these changes to our benefit, we should be ready to adapt how we manage our projects. Which is why these five ideas need to be put to rest. They're archaic and inefficient, and instead of bringing you closer to your goals, they end up obstructing your road to success. Your turn: What project management ideas do YOU think should be extinct? Hit the comments and tell us.

Project Management 7 min read

Project Management Methodologies Review (Part 1)

Choosing a project management methodology is like choosing which recipe to follow when baking chocolate chip cookies. One recipe might use room-temperature butter while another recommends melted margarine, or call for dark chocolate instead of semi-sweet chips. Each recipe gives you delicious cookies, but the steps, ingredients and techniques are all a little different to suit your tastebuds. You should pick your PM methodology based on your available ingredients: project constraints, timeline, tools, and people. Read through this list of common project management methodologies and see if they sound like they fit your project or organization. We include brief descriptions, pros, and cons for each, and if one captures your attention, we definitely encourage further research. Here's the first half of our PM methodologies list: 1. Adaptive Project Framework (APF)The APF method strives to learn from experience. These projects begin with a Requirements Breakdown Structure to define strategic project goals based on product requirements, functions, sub-functions, and features. As they proceed, teams continually evaluate previous results to improve policies and practices at each stage of the project lifecycle. Clients/stakeholders can change project scope at the start of each stage so the team can produce the most business value. PRO: This is a good approach for when you know what your goal is and aren't sure of the best way to get there.CON: Due to its flexibility, the Adaptive Framework may lead to project delays or increased budgets. 2. Agile Project ManagementGreat chefs taste their food as they cook so they can add new ingredients to create the best dish. Agile is like tasting our project as we go and adjusting it accordingly. Planning begins with clients describing how the end product will be used, its benefits, and so on, so the team gets a good understanding of the expectations. Once the project has begun, teams cycle through the process of planning, executing, and evaluating tasks — which might change the final deliverable. Continuous collaboration is key, both among team members and with project stakeholders, to make fully-informed decisions. PRO: This approach is beneficial for creative projects with goals that are flexible and can be modified midway.CON: Timelines and budgets are difficult to define, and stakeholders must have the time and desire to be actively involved in the day-to-day work. Confused about the difference between APF and Agile? We’ll break it down for you: with APF, your end goal is clear, but your method for achieving that goal will change based on your experience at each stage of the project. With Agile, your end goals are less defined. Each stage brings feedback from stakeholders to help guide your decisions and improve or alter the final product. 3. Benefits RealizationThis project management methodology redefines success as not just delivering the package on time and with money to spare, but achieving a desired benefit. Here's an example: say your clients want to increase their sales conversion rate by 15%. They hire you to manage the development of a new CRM software that will help the sales team personalize their communications, track sales data, and determine ideal communication timelines. You deliver a CRM with those features on time and within budget. Success, right? What if your client's sales conversion rates only increase by 5%? With benefits realization, your project isn't successfully completed until the client's desired benefits are achieved — in this case, until the sales conversion rate is up 15%. PRO: This approach ensures that your projects contribute real value to the business and deliver the end results your stakeholders care about.CON: Benefits aren't always exact, measurable, or scientific, so it can be difficult to know if they've been achieved — or if your project actually contributed to that success. You'll need to put careful thought into developing effective metrics to measure the outcomes of your project, such as ROI, process capability, faster delivery times, or higher customer satisfaction. 4. Critical Chain Project Management (CCPM)Project delays are usually caused by resources that aren't available when you need them. CCPM avoids that by building a project schedule that first identifies a "critical chain" of tasks and then reserving resources for those tasks. Your project timeline may be longer, but you’ve got a higher probability of predicting realistic deadlines. PRO: Tasks can be collaborated on because you know that all key players are available when you need them.CON: This approach may not be effective for projects with short deadlines, since CCPM plans build in extra time buffers along the critical chain. 5. Critical Path Method (CPM)Determine your project's shortest timeline and adjust to shifting deadlines using CPM. You'll start by looking at all the tasks absolutely necessary to complete your project, and then estimating completion times for each step, including task dependencies, milestones, and final deliverables. PRO: Specific dates can be assigned to each task, so managers can compare what should be happening with what is happening on a daily basis. It's optimal for projects with short deadlines.CON: Critics say a major drawback is that CPM doesn’t consider resource availability in planning, so you may be left with an overly optimistic plan. 6. Event Chain Methodology (ECM)Most projects don’t go exactly according to plan. Risks are difficult to identify and analyze, and project managers may be under pressure by stakeholders to create optimistic timelines, budgets, or deliverables. Event chain methodology helps recognize and plan for potential risks that may lie outside the project scope. By using techniques like Monte Carlo Analysis and Event Chain Diagrams, project managers can see how external events affect project tasks and determine the probability of certain risks occurring. PRO: By visualizing the relationship between external events and tasks, managers can create more realistic project plans.CON: It's easy to forget that external events aren't just threats to your project — they can also present opportunities. Don't automatically squash all potential risks and fail to capitalize on fortunate circumstances. 7. Extreme Programming (XP)XP features short development cycles, frequent releases, and constant client collaboration. Productivity is high, and the approach is well-suited to complex or undefined projects. These teams allow for change within their sprints; if the team hasn't started work on a feature, a similar task can be swapped out to replace it. Teams avoid overworking themselves through effective collaboration and by writing the simplest possible code to produce the desired feature. PRO: XP is efficient, with a focus on simplicity. Teams work at a sustainable pace, meaning no 80-hour work weeks leading to burnout and low-quality output.CON: Critics warn that the XP approach's strength lies too much in the ingenuity of unique team members rather than with process itself. 8. KanbanIf a continuous workflow and outputting a slow and steady stream of deliverables are your main priorities, Kanban is your man. Managers create visual representations for the workflow (often using a whiteboard or sticky notes) to uncover process problems and prevent tasks from stalling as "works in progress." The sticky notes move across the board to tangibly represent project progress. PRO: Kanban helps teams understand where their time is really being spent so you can improve efficiency.CON: Variations in customer demand — like the start of the holiday season, or a drop-off due to a recall — can make Kanban inefficient, since it’s designed to produce a steady output. Find a project management methodology you like? Itching for more bite-sized breakdowns? Stay tuned for Part 2 of this post, where we'll cover 8 more essential methodologies as the next chapter in your PM handbook. Does your company use one of these PM methodologies? Is it good? Bad? Tell us about your experience with it in the comments below. Related Posts: • Project Management Basics: A Review of PM Methodologies (Part 2) • A Crash-Course in Project Management Methodologies (Infographic)

Project Management 7 min read

Project Management Methodologies: A Quickstart Guide (Part 2)

Now that you’ve mastered the lingo and have a firm grasp on our first 8 common Project Management methodologies, you’re starting to settle into your new PM role. You’re gearing up for your first project kickoff, and the boss is back in your office: “So, let’s talk methodologies. What do you think is the best strategy for our company?” Gulp. Don’t panic — you’ve got this. We’ll give you the rundown on 8 more PM methodologies so you can choose the winning approach every time. Here are the next 8 project management methodologies: 1. Lean PM"Waste not, want not!" Lean project management is all about finding the path of least resistance to get the results you want. You identify and cut out waste (or mura), starting by examining your full work-process breakdown to find and eliminate bottlenecks and delays. Teams focus on the project's true customer value, and on continuous process improvement. The goal is to do more with less: deliver high value, high quality work with less manpower, less money, and less time. PRO: This approach is especially helpful if you need to find ways to cut your budget, meet quick deadlines, or get big results with a small team.CON: Since the ultimate goal is to get things done faster and cheaper, stakeholders need to make prompt decisions and be prepared to stick to those decisions -- weighing options for 2 weeks interrupts the Lean process. 2. PRINCE2Not to be confused with the first Prince. Also known as "PRojects IN Controlled Environments." The project must have a business justification, so the first step is identifying a clear need, targeted customer, realistic benefits, and thorough cost assessment. A project board owns the project and is responsible for its success, while a project manager oversees day-to-day activities. PRO: The extensive documentation involved in PRINCE2 projects can be very helpful with corporate planning and performance tracking.CON: It can be difficult to adapt to project changes, since a lot of effort goes into creating and maintaining those documents and logs at each stage of the process. 3. PRiSMWant to go green? PRiSM (PRojects integrating Sustainable Methods) blends project planning with environmental sustainability measures. PRO: Aligning corporate strategy with social responsibility can bolster a company's reputation, plus you could benefit from reduced energy, waste management, and distribution costs.CON: Environmental responsibility must be a priority at every level of the company -- from executives to managers -- for it to be truly successful. 4. Process-Based Project ManagementIt's all about "mission accomplished." Every project is defined by your company mission or vision statement, whether that be "Feed the Homeless" or "Improve Global Collaboration." Before project kick-off, the plan is analyzed to see if it will live up to your mission statement; if it won't then all strategies and goals are adjusted in order to meet that objective. PRO: This approach helps ensure that every project aligns with, and adds value to, the organization's strategic vision.CON: Adjusting every team's projects and processes to fit the mission can be very time-consuming. And it doesn't allow for side projects, so if your company wants to take on tasks unrelated to your values you'll have to revisit your company mission statement first. 5. Scrum"Productivity" is the name of the game. Small teams are facilitated by a scrum master, whose job is to remove any barriers to team progress. Work is typically done in a series of two-week sprints, and team members are in constant communication through daily scrum meetings. PRO: New developments can be tested quickly and mistakes are fixed right away.CON: Scrum projects are prone to scope creep. Because the team is a close unit, one member leaving can also disrupt the whole project. **Confused about the difference between Scrum and XP (from Part 1)? XP teams tackle tasks in a strict customer-determined order, whereas Scrum teams can determine their own timeline. Additionally, XP allows similar tasks to be swapped within a sprint, but Scrum tasks are meant to be set in stone until the end of the sprint. 6. Six SigmaWhat's your sigma rating? Six Sigma is a quality-improvement process aimed at reducing the number of defects in manufacturing and industrial sectors, or the bugs in software development. A rating of "six sigma" indicates that 99.99966% of what is produced is defect-free. PRO: Six Sigma is a very proactive methodology, and it examines the entire production process to identify process improvements even before defects appear.CON: This holistic approach may also lead to rigidity in the planning process, which could limit your team's creativity and innovation. 7. Lean Six SigmaIt combines Lean's efficiency with Six Sigma's statistics-based process improvement. It corrects workflow problems and eliminates waste by helping you understand how work gets done and identify which aspects of your project are most valuable to the client or customer. PRO: In addition to making your projects more efficient and cost effective, Lean Six Sigma keeps employees actively engaged in process improvement, leading to a sense of ownership and accountability.CON: Lean Six Sigma usually involves major change to the way work gets done, so make sure you -- and company execs, stakeholders, and other managers -- are prepared for the amount of time, effort, and resources needed to be successful with this method. 8. WaterfallImagine the path of a waterfall: The river runs from the top and flows down to the bottom without steering away from the main course. It's the same in project management. With clearly defined goals and a set timeline, teams work through tasks in sequence, completing one before moving on to the next in line. PRO: Extensive planning goes into this approach, and this thoroughness often results in more accurate timelines and budgets.CON: It is difficult to adapt to any project changes — or modify and correct previous steps (water can't run backwards!) — so you'll need to be proactive in anticipating problems before they can affect your flow. 16 methodologies later, and we're confident that you have the knowledge you need to confidently lead your team to success. Now it's time to decide which is best suited for your company and projects, and get things done! Which PM Methodology does your company use? Share your first-hand pros and cons in the comments below. See this next: All 16 Project Management Methodologies in One Simple Infographic

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Deep Dive Into Development: Understanding the Vertical Slice Methodology