High-level design

High-level design (HLD) explains the architecture that would be used for developing a software product. The architecture diagram provides an overview of an entire system, identifying the main components that would be developed for the product and their interfaces. The HLD uses possibly nontechnical to mildly technical terms that should be understandable to the administrators of the system. In contrast, low-level design further exposes the logical detailed design of each of these elements for programmers.

Purpose

Preliminary design—In the preliminary stages of a software development, the need is to size the project and to identify those parts of the project that might be risky or time consuming.
Design overview—As the project proceeds, the need is to provide an overview of how the various sub-systems and components of the system fit together.

In both cases the high-level design should be a complete view of the entire system, breaking it down into smaller parts that are more easily understood. To minimize the maintenance overhead as construction proceeds and the lower-level design is done, it is best that the high-level design is elaborated only to the degree needed to satisfy these needs.

High-level design document

A high-level design document or HLDD adds the necessary details to the current project description to represent a suitable model for coding. This document includes a high-level architecture diagram depicting the structure of the system, such as the database architecture, application architecture (layers), application flow (navigation), security architecture and technology architecture. ^[1]

Design overview

A high-level design provides an overview of a solution, platform, system, product, service or process.

Such an overview is important in a multiproject development to make sure that each supporting component design will be compatible with its neighbouring designs and with the big picture.

The highest-level solution design should briefly describe all platforms, systems, products, services and processes that it depends on and include any important changes that need to be made to them.

In addition, there should be brief consideration of all significant commercial, legal, environmental, security, safety and technical risks, issues and assumptions.

The idea is to mention every work area briefly, clearly delegating the ownership of more detailed design activity whilst also encouraging effective collaboration between the various project teams.

Today, most high-level designs require contributions from a number of experts, representing many distinct professional disciplines.

Finally, every type of end-user should be identified in the high-level design and each contributing design should give due consideration to customer experience.

References

↑ https://people.ok.ubc.ca/rlawrenc/research/Students/CJ_05_Design.pdf

"Designing in a Big Way - a practical guide for managers", High Level Designs Ltd,
High Level Design Document sample format

http://users.csc.calpoly.edu/~jdalbey/205/Deliver/designDocFormat.html

Communication design	Advertising Book design Corporate design Exhibit design Film title design Graphic design Environmental Motion Postage stamp design Print design Illustration Information design Instructional design News design Photography Retail design Signage / Traffic sign design Typography / Type design Video design Visual merchandising

Environmental design	Architecture Architectural lighting design Building design Passive solar Ecological design Environmental impact design Garden design Computer-aided Healthy community design Hotel design Interior architecture Interior design EID Keyline design Landscape architecture Sustainable Landscape design Spatial design Transition design Urban design

Industrial design	Automotive design Automotive suspension design CMF design Corrugated box design Electric guitar design Furniture design Sustainable Hardware interface design Motorcycle design Packaging and labeling Photographic lens design Product design Production design Sensory design Service design

Interaction design	Experience design EED Game design Level design Video game design Hardware interface design Icon design Immersive design Information design Sonic interaction design User experience design User interface design Web design

Other applied arts	Public art design Ceramic / glass design Fashion design Costume design Jewelry design Floral design Game art design Property design Scenic design Sound design Stage/set lighting design Textile design

Other design & engineering	Algorithm design Boiler design Conceptual design Database design Drug design Electrical system design Experimental design Filter design Job design Integrated circuit design Circuit design Physical design Power network design Nuclear weapon design Nucleic acid design Organization design Process design Processor design Protein design Research design Social design Software design Spacecraft design Strategic design Systems design

Approaches

Tools
Intellectual property
Organizations
Awards

Tools	AAD Architectural model Blueprint Comprehensive layout CAD CAID Virtual home design software CAutoD Design quality indicator Electronic design automation Flowchart Mockup Product design specification Prototype Sketch Storyboard Technical drawing Web design program Website wireframe

Intellectual property	Community design Design around Design patent Geschmacksmuster Industrial design rights European Union

Organizations	AIGA Chartered Society of Designers Design and Industries Association Design Council International Forum Design The Design Society Design Research Society

Awards	European Design Award German Design Award Good Design Award (Chicago) Good Design Award (Japan) Graphex IF product design award James Dyson Award Prince Philip Designers Prize

High-level design

Purpose

High-level design document

Design overview

References

See also