Please Explain Low Level Design(LLD) and High Level Design (HLD) in the Design phase of SDLC

Showing Answers 1 - 14 of 14 Answers

punereddy

  • Mar 25th, 2006
 

HLDBased on SRS, software analysts will convert the requirements into a usable product.They will design an application, which will help the programmers in coding.In the design process, the product is to be broken into independent modules and then taking each module at a time and then further breaking them to arrive at micro levelsThe HLD document willcontain the following items at a macro level: - list of modules and a brie description of each module - brief functionality of each module - interface relationship among modules -dependencies between modules - database tables identified along with key elements - overall architecture diagrams along with technology detailsLLDHLD contains details at macro level and so it cannot be given to programmers as a document for coding.So the system analysts prepare a micro level design document, called LLDThis document describes each and every module in an elaborate manner, so that the programmer can directly code the program based on this.There will be at least 1 document for each module and there may be more for a module.The LLD will contain: - deailed functional logic of the module, in pseudo code - database tables, with all elements, including their type and size - all interface details with complete API references(both requests and responses) - all dependency issues -error message listings - complete input and outputs for a module(courtesy 'anonimas')

sri

  • Apr 5th, 2006
 

High –Level Design or System Design (HLD)

 

High – level Design gives the overall System Design in terms of Functional Architecture and Database design. This is very useful for the developers to understand the flow of the system.  In this phase design team, review team (testers) and customers plays a major role. For this the entry criteria are the requirement document that is SRS. And the exit criteria will be HLD, projects standards, the functional design documents, and the database design document.

 

Low – Level Design (LLD)

 

During the detailed phase, the view of the application developed during the high level design is broken down into modules and programs. Logic design is done for every program and then documented as program specifications. For every program, a unit test plan is created.

 

The entry criteria for this will be the HLD document. And the exit criteria will the program specification and unit test plan (LLD).

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gopusted

  • Apr 30th, 2006
 

HHD is the first output in your system design phase(in SDLC).Here we design the overall architecture of the system.The main functional or all the core modules are given shape here.This also include contr0l flow b/w main modules,e-r status etc.

main out-put's are

E-r diagram,flow chart,DFD's etc

LLD we create more detail and specific design of the system.how exactly we make the dB structure,interface design etc

Main output's are

DB's schema,frameworks,Interface desins etc 

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sudhakar2068

  • Sep 12th, 2006
 

High Level Design(LLD) :It design the over all architecture of the entire system from main module to all sub module.

Low Level Design(LLD) :It defines Internal logic of corresponding submodule designers are preparing individual LLD to Every module.

 sudhakar kolla.

If you have doubts can ask me.

My Email:kollasudhakar2005@yahoo.co.in.

My Number:09819859346.


 

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shashi

  • Mar 7th, 2007
 

can u please let me know the names of LLD design Patterns, 

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SIVAKUMAR

  • Nov 22nd, 2007
 

High Level Design is defined as to check the fuctionality of the internal code in the program

Low Level Design is deined as to check the documents,other features of the program

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devanggoel

  • Jun 5th, 2009
 

For people who have been involved in software projects, they will constantly hear the terms, High Level Design (HLD) and Low Level Design (LLD). So what are the differences between these 2 design stages and when are they respectively used ?

High Level Design (HLD) gives the overall System Design in terms of Functional Architecture and Database design. It designs the over all architecture of the entire system from main module to all sub module. This is very useful for the developers to understand the flow of the system. In this phase design team, review team (testers) and customers plays a major role. For this the entry criteria are the requirement document that is SRS. And the exit criteria will be HLD, projects standards, the functional design documents, and the database design document. Further, High level deign gives the overview of the development of product. In other words how the program is going to be divided into functions, modules, subdivision etc.

Low Level Design (LLD): During the detailed phase, the view of the application developed during the high level design is broken down into modules and programs. Logic design is done for every program and then documented as program specifications. For every program, a unit test plan is created. The entry criteria for this will be the HLD document. And the exit criteria will the program specification and unit test plan (LLD).

The Low Level Design Document gives the design of the actual program code which is designed based on the High Level Design Document. It defines Internal logic of corresponding submodule designers are preparing and mapping individual LLD’s to Every module. A good Low Level Design Document developed will make the program very easy to be developed by developers because if proper analysis is made and the Low Level Design Document is prepared then the code can be developed by developers directly from Low Level Design Document with minimal effort of debugging and testing.

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MN

  • Sep 23rd, 2011
 

thanks for the info. i am posting a question in my answer and that question to the forum is, "I am implementing HRMS, FMS and SCM modules of Oracle EBS R 12X with customization and the SCM module running on different instances. my client has asked me for a low level diagram of my solution. how do i go about this? plus, is there an automated tool that allows me to do this ?
thanks

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Pejman Nikaeen

  • Sep 27th, 2011
 

It defines the actual logic for each and every component of the system. Class diagrams with all the methods and relation between classes comes under LLD.

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NISHANK

  • Jul 2nd, 2012
 

NO, it is done by designing team.

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sudheera

  • Aug 30th, 2012
 

in LLD what type of information is there like text or uml diagrams

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Stanley

  • Aug 22nd, 2013
 

Tester dont need to do anrthing of HLD, only for Planner or Designer.

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