Explain about HLD and LLD ?

Answer Posted / devang

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 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.

Is This Answer Correct ?    107 Yes 3 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is song in infrmatica...?

1693


I have worked on Informatica 7.1.1. I want to know the answer for the below question. Target is not created initially.Then how to take the DDL script from the source and run the Mapping by creating the Target dynamically?Is it possible by SQL Transformation?

1474


What are the main features of Oracle 8i with context to datawarehouse?

1691


What does refresh system mean, and what are its distinctive choice?

574


How can we use mapping variables in informatica? Where do we use them?

628






What happen if you have 3 ports in SQ and 4 ports in SQL override of SQ( provided all ports are in same order and they are connected with proper source and target)? Also what happens when I have 4 ports and will extract 3 values in SQloverride.. What will be the value in 4th port ?

1191


How to create or implement slowly changing dimension (SCD) Type 2 Effective Date mapping in informatica/Flagging mapping in informatica/visioning mapping in informatica?

718


I have done MBA in 2008. i got job as business analyst in 2008 january through consultany. but after 3 months they are giving training Informatica developer. now iam continuing this job. my question is when iam going to interview HR people ask me many times like this " YOU ARE MBA GRADUATE. HOW YOU ARE SELECT THIS POSTION. IAM EXPLAINING WHAT I HAVE MENTION ABOVE". PLEASE TELL HOW IAM TELLING THIS QUESTION ANSWER.

1635


EXL informatica Questions

941


What is source qualifier transformation in informatica?

584


Define pmcmd command?

631


How we can create indexes after completing the loan process?

735


What are the components of Informatica? And what is the purpose of each?

628


Explain how many types of dimensions are available in informatica?

602


How can you increase the performance in joiner transformation?

717