Laying the Foundation: How the HLD Sets the Stage for Success

High-Level Design (HLD), referred to as Initial Detailed Design (IDD) for some, may be considered a crucial stage for bridging the gap between conceptual and detailed design stages. This phase focuses on developing a design that, while not yet at the quality of a Low-Level Design (LLD), is sufficiently detailed to minimize changes later in the process and provide a near-final design blueprint. 

Join us as we guide you through the creation of what we call an Initial Detailed Design (IDD), a more comprehensive approach than the industry-standard High-Level Design (HLD). In the article below, Lelia outlines the crucial steps our team takes to deliver a design that meets and exceeds our clients' expectations. 
 
The HLD aims to create a design as close as possible to the Low-Level Design. This involves defining the architecture along with physical and network elements of the design in a way that reduces the need for extensive changes after field surveys and detailed design stages. 

Before starting the HLD, the client must agree on an established architecture. This will form the Complete Architecture Playbook (CAP), which includes all fundamental rules and guidelines necessary for the project. The CAP serves as a foundational document, guiding the HLD process and defining its limitations. Read here for a more comprehensive view on what a CAP is: https://bit.ly/4ecwGzX 

After the CAP has been established, a preliminary Bill of Materials (BOM) is prepared during the HLD phase. This BOM provides an estimate of the materials needed, including cables and equipment, based on the design. It helps clients have a better view of network costing, sourcing, and planning with the consideration of factors like permitting and/or logistics. 

• The HLD involves a detailed desktop-level design approach. The design team uses the established architecture and CAP to create a focused design, although it is not as detailed as the final Low-Level Design. 

• Changes identified during field surveys can affect the HLD output. For instances of 1) pole location change: If a pole’s location changes, it will impact one of many factors such as messenger span and the length of cables running between poles. 2) If equipment cannot be attached to a pole after the survey, the BOM and design will need adjustments to accommodate these constraints. 

• The HLD provides a framework/blueprint, but it remains flexible to accommodate changes.  However, be mindful of the adjustments that may be necessary. If the modifications identified during field surveys and further design iterations are too extensive to be addressed within the HLD, it might be prudent to initiate the Low-Level Design (LLD) at that point. This approach ensures that the final design can adapt effectively to real-world conditions and requirements. 

In addition to data preparation, our design team utilizes preprocessing design tools, splicing tools, and various post-processing tools. 

The preprocessor tool begins by taking in data that has undergone preparation, and converting it into a standardized, Biarri-tool-readable format. This process also generates a candidate network, which will act as a reference for the subsequent stages of the design process. The Solve design tool generates a network plan by referencing the output from the preprocessing stage. This stage provides the candidate network, which the Solve tool uses as a foundation for creating the final design.  

By emphasizing detailed architecture early on, the HLD helps minimize changes later and ensures that the final design effectively adapts to real-world conditions.