Foreword
========

At ECMWF we have a comprehensive list of computational workflows called *suites* that produce both operational and
research data or provide system maintenance. The design of these suites has evolved over time to a high level of complexity in the workflow
management system (:ecflow-docs:`ecFLow </>`), incorporating a range of different styles and methodologies. Many
recommendations for best practices and standards exist, but mainly only at the working group level, thus serving mostly
specific use cases and not being transferable across ECMWF. The different requirements for research, development and
operational suites present challenges in maintaining a consistent approach.

Requirements of research, development and operational suites
------------------------------------------------------------

- Research and development
    - Runs on historical dates, retrieved from archive or another experiment
    - Requires configurability and flexibility
    - On-the-fly debugging
    - Collaboration with a range of users
    - Ability to run in test mode

- Operations/production
    - Runs on the latest date using observation retrievals
    - One fixed configuration
    - Run with dedicated users and special permissions to avoid outside interference
    - As efficient as possible
    - Finely tuned to a schedule
    - Features to ensure reliability and avoid or fix common problems
    - Clear documentation (that can be followed by a stressed person at 3am)

Designing suites that are incompatible in either can lead to inefficiencies and difficulties in collaboration, debugging,
and transitioning between these use cases within suite lifecycle.

Aim and scope of these guidelines
---------------------------------
This document aims to provide a coherent set of guidelines for suite development across ECMWF. They were developed by
suite developers and users from across the centre to promote a consistent, structured, and modern approach that is
applicable across research, development, testing, and operational environments. They are expected to be useful for new
or external users as well as experienced ones alike. While these guidelines should serve as a solid foundation for
improvements, it is anticipated that they will be further refined and expanded over time to adapt to evolving needs and
applications.