Week 7 Learning Journal- CST438

This week’s module was a distinct shift from the Agile methodologies we have been focusing on for most of the course. It was interesting to dive into the "Plan and Document" process, often called Waterfall, and see how it contrasts with the iterative approach we are used to. The most obvious difference is the structure itself. The lecture described this process as a series of phases- requirements, design, implementation, and verification, that flow downward like water. In our Agile labs, we are used to doing a little bit of design, coding, and testing all at the same time within a sprint. However, with the Plan and Document approach, there is a strict rule that you generally need to finish the current phase and produce a specific document, like the System Design Document, before you can move on to the next stage .

One of the biggest takeaways for me was understanding why someone would choose this rigid structure over Agile. I used to think Waterfall was just "old fashioned," but the lecture explained that it solves specific problems that Agile struggles with. For example, Agile relies heavily on the customer being constantly available to answer questions and give feedback on user stories. If you have a client who doesn't want to be involved daily, Agile falls apart. In those cases, the Plan and Document method is actually better because you create a massive, detailed System Requirements Specification (SRS) upfront . This allows the developers to go away and build the software without needing to pester the client every day.

I also found the discussion on cost estimation and planning really practical. In Agile, it feels like we often guess about the final delivery date because the scope is always changing. The professor mentioned that Agile cost estimates are often not very accurate at the start. Contrastingly, because the Plan and Document process forces you to finalize requirements and design early, you can use tools like PERT charts to calculate the critical path. This lets you give a client a firm price and delivery date, which is something many businesses require . It made me realize that while Agile is great for flexibility, the Plan and Document process offers a level of predictability and stability that is necessary for large-scale or fixed-contract projects.