How can you implement the Waterfall model in Information Systems development?

The waterfall method in systems development has been proven ineffective and prone to error. While setting goals is important, attempting to set scope up front and managing to that leads to a lot of overhead. The Standish Chaos report annually studies 150000 projects over all areas of system development and consistently find that only 20% of all system projects managed this way fully succeeded. This is twice as ineffective as agile software development

La première étape du modèle Waterfall dans la gestion de projet SI, comme souligné dans mon mémoire de recherche, requiert une identification méticuleuse des parties prenantes et une planification soigneuse des entretiens et ateliers pour une compréhension approfondie des exigences. L'analyse approfondie des besoins, préconisée dans mes recherches, doit précéder une documentation détaillée du périmètre du projet. Le document résultant doit être validé formellement, instaurant ainsi une base solide pour la réussite du projet SI selon la méthodologie Waterfall.

I am surprised someone is still promoting waterfall... As you may see from some of the comments so far, this approach is not considered up-to-date (already in the early eighties there were better ones - and progressed ever since into SSADM, Extreme programming, then Agile etc.). Read the book "Mythical Man Month" by Brooks to start with (that is what I give to my beginner Software Engineering students).

In my experience there is a need to revise the scope of all elements on a regular basis because the information gathered throughout the entire project can, and usually does, change the initial assumptions.

This depends on type of the project you re delivering. If you are working on a fixed cost for the entire project you can't afford not to define the scope upfront. You will be over budget.

A melhor maneira de implementar o modelo Waterfall é seguir uma abordagem sequencial e linear, dividindo o projeto em fases bem definidas, como: requisitos, projeto, implementação, teste e manutenção. Cada fase deve ser concluída antes de passar para a próxima, garantindo uma progressão ordenada do projeto. Além disso, é importante documentar claramente cada etapa e seus resultados, garantindo uma transição suave entre as fases e facilitando a detecção e correção de problemas. Espero ter contribuindo

It is important to have infrastructure-level design or “just enough” design; however, “Big Design Upfront” is frequently a reason software projects fail according to the Standish Chaos report. It’s critical that design includes proofs of concept and ensures all stakeholders are participating. This is a strength of the Scaled Agile Framework.

The design phase in the Waterfall model is critical as it sets a blueprint for the entire system. It's important to note that this phase demands thoroughness since changes later in the development process can be costly and time-consuming. The use of standardized design documentation and tools, like UML for modeling, ensures clarity and consistency across the team. Moreover, considering design patterns and best practices during this phase can greatly improve the maintainability and scalability of the system. Prototyping, as part of this phase, can also be invaluable for validating design choices and gathering early user feedback.

Designing a waterfall model does not prevent scope creep. Waterfall is best suited to manage maintenance projects by defining the scope and adhering to the budget. Scope creep will occur, but the work is not critical and can be delivered incrementally throughout the timeline with minimal impact to the budget.

No modelo em cascata acho fundamental usar uma estrutura analítica do trabalho listando todas as tarefas necessárias para chegar à entrega final. Além do cronograma com as tarefas definidas, estimando o tempo que cada tarefa levará. Mapeando o cronograma no gráfico de Gantt com os custos à construção do orçamento.

The majority of software companies have adopted either and agile or hybrid process as it has been demonstrated that if no code is developed until after design, key requirements are missed and critical non-functional design assumptions are also missed.

Vou compartilhar minha experiência com desenvolvimento de sistema no modelo em cascata. 1) Atribuir tarefas à equipe Costumo atribuir as tarefas a partir de um gráfico de Gantt e adicionar descrições, prioridade, etc. 2) Monitorar e acompanhar Enquanto a equipe executa as tarefas, acompanho seu progresso para ter certeza de que o projeto está avançando de acordo com o cronograma. 3) Gerenciar recursos e carga de trabalho 4) Relatório às partes interessadas Costumo me reunir e combinar uma programação regular para apresentações. 5) Teste Depois que a equipe entregar o sistema funcional, deverá passar por testes extensivos para garantir que tudo esteja funcionando conforme projetado. 6) Entrega Depois que todos os bugs forem resolvidos!

La phase de développement dans le modèle Waterfall implique en termes d’étapes : le Codage (Implémentation): Dans cette étape, les programmeurs traduisent la conception du SI en code source en suivant les spécifications et les exigences définies lors des phases précédentes (analyse des besoins et conception). Le codage est séquentiel et linéaire, ce qui signifie que chaque module est développé un à un, sans chevauchement. Ensuite, vient l’étape des Tests d’intégration qui sont effectués pour vérifier que les différents modules ou composants du SI fonctionnent correctement ensemble. Pour les Frameworks, ce sont des structures logicielles qui fournissent des fonctionnalités prêtes à l’emploi pour accélérer le processus de codage.

It would be a seamless continuation of the design process but moving closer to full development. See my comments on the design process.

The deployment phase in the Waterfall model is critical, as it's the first-time end-users interact with the system. It's essential to have a rollback plan in case the deployment encounters issues. Moreover, thorough documentation and training are vital to ensure a smooth transition. This phase often includes data migration, which must be carefully managed to prevent data loss or corruption. The success of deployment is measured by system stability and user adoption rates, indicating the system's readiness for the final phase.

Atualmente, posso afirmar que a maior mudança no desenvolvimento de software é a frequência das implantações. As equipes de produto implantam versões para produção mais cedo e com mais frequência. Ciclos de lançamento de meses ou anos estão se tornando raros. Usando uma arquitetura orientada a serviços (SOA) e uma abordagem de micros serviços, os desenvolvedores podem projetar uma base de código para ser modular. Isso permite escrever e implantar alterações em diferentes partes da base de código simultaneamente!

If all the steps I outlined before this one are adopted the deployment process should be a confirmation of all the assumptions and adjustments made throughout the SDLC that I outlined for the other steps in the process. It would be a seamless evolution that is built on good project development practices.

Pour optimiser de maintenance, il faut : une Surveillance continue : via des mécanismes automatisés pour détecter les problèmes de performance. Utiliser des outils de surveillance réseau et incidents pour identifier les pics de charge avérés et potentiels. Une évaluation régulière des performances (temps de réponse, disponibilité). Suivi des fonctionnalités : si toujours pertinentes pour les utilisateurs. Gestion des correctifs et mises à jour : en les testant avant déploiement (tests de non-régression). Documentation (procédures de maintenance)et communication avec les parties prenantes. Formation continue : du personnel chargé de la maintenance sur les nouvelles fonctionnalités et les meilleures pratiques.

If the project is well managed, maintenance is just another step that takes in consideration the resources needed to keep the system running for its expected lifetime. Resources to be considered: Skills, system updates, type and number of resources, level of service needed to keep the customers happy, budget to support all the items above. If this is a system that is intended to be sold to many customers, executive and management personnel, marketing, sales and sales support staff, customer support, accounting, HR, etc. will be needed.

It is important to note that the frequency of audits and assessments may vary based on the organization's risk profile and the sensitivity of the data it handles. It is recommended to consult with legal and compliance professionals to determine the appropriate frequency for data privacy audits and assessments based on your specific circumstances.

Using a pure waterfall method is not ideal because it assumes a project's requirements and scope are fully known and will not change, which is rarely the case in real-world projects. This rigid structure makes it difficult to incorporate feedback or changes late in the project, leading to potential mismatches between the final product and user needs. Additionally, it delays testing until after the development phase, which can result in the discovery of issues late in the process, making them more expensive and time-consuming to fix. The waterfall method's lack of flexibility and iterative refinement often leads to longer delivery times and increased costs.