Development Process for Web-Enabled Applications – High Level Design

High Level Design

Objective

The objective is to prepare Higher Level Design (HLD) based on the Software Requirement Specifications (SRS) document. This stage also involves preparation of the draft version of various manuals, System test plans. The Client and the QA representative should approve all these documents.

Entry Criteri a

High Level Design Process starts when:

· Software Requirement Specifications reviewed and approved

· Change Requirement Specifications reviewed and approved

· Project Plan reviewed and approved

Process Description

Software design process is a set of iterative steps that enable the designer to describe all aspects of the software to be built. This process is carried out in two phases, viz., High Level Design and Low Level Design.

High-level design gives a holistic view of the software and focuses on the hardware and software architecture, the man-machine interface and the division of the product into manageable units.

The first and foremost task is to identify the design paradigm. It is the responsibility of the designer to choose an appropriate methodology and thereon must follow the standards as defined by and for that particular methodology, unless specified by the customer..

Regardless of the design methodology that is used, a set of fundamental concepts that are applied to data, architectural and procedural design are as follows.

Concept	Activities	Responsibility
System Architecture	1. Model the System Architecture. 2. Establish the interrelationship between the system elements, which relates to the following processing areas. · User Interface · Input · System Function and Control · Output · Maintenance 3. Prepare a context Diagram or an Architectural Diagram depending upon the methodology.	Project Manager
Identification Of Modules	1. The software should be logically partitioned into components that perform specific functions 2. The module is designed so that the information contained within a module is inaccessible to other modules that have no need for such information. 3. Prepare a Functional Decomposition Diagram, if required.
Logical Data Modeling	1. Select logical representations of data structures , identified during SRS phase 2. Prepare the Logical data Flow Diagram 3. Prepare the Entity-Relationship Diagram
Process Modeling & Control Flow identification	1. Identify the control relationships among various modules. A Control Flow Diagram will be prepared , if required 2. Define the interfaces that enable the data flow between these modules
Preparation of HLD document,Test Plans, Manuals	1. Prepare a HLD document and ,that encompasses the details of the design process 2. Prepare the System Test Plans 3. Prepare User and System Manuals.
Review & Approval of HLD document, test plan, manuals	1. The HLD document, Test Plans, Manuals are reviewed by the Project Team, QA Team and the customer, if required. 2. Update these documents based on the review results. 3. Update the Project Plan and CM 4. The review checklist for High Level Design document appears in the procedure MT/TECH/FTR.

Deliverables from the process

· HLD document

· System Test Plan

· Draft copies of user manual, System manual

· Reviewed and updated Project Plan (PP)

· Reviewed and Updated Configuration Management Plan (CM)

Exit Criteria

The HLD process is completed when:

· Reviewed and approved High Level Design document available

· Reviewed and approved System Test Plan are available

· Draft versions of Systems Manual and User Manual are available

· Updated Project Plan (PP) and Configuration Management Plan (CM) are available

· Traceability matrix updated (Refer to 12.3.5 for format of this matrix)

Low Level Design