# Technical writing/SDLC EE

back to Technical Writing Level 1 --Chatsami (discuss • contribs) 00:07, 13 November 2014 (UTC)=The Systems Development Life Cycle=
The Systems Development Life Cycle (SDLC) is a logical process that helps to design good new products and software efficiently. The SDLC system emphasises planning.
The SDLC system was developed because:
* Before the SDLC many government projects failed.
* Many projects were delivered to the Sponsor' late ( the Sponsor is the Person or organisation that pays for the project).
* Many projects cost more than double the original estimate
--Chatsami (discuss • contribs) 00:04, 13 November 2014 (UTC)==The reason why projects failed==
* Inventors invented what they imagined, not what was needed.
* Products were designed without market research.
* The inventor or developer did not know if anyone would buy the product until the end of the process.
* Inventors and developers did not have a logical systematic method when they started to design and develop ideas.
* The inventor or developer added features to the product that delayed the product launch (many of these features did not improve the performance or make the product easier to use).
--Chatsami (discuss • contribs) 00:04, 13 November 2014 (UTC)==How the SDLC works== The SDLC is a logical system that checks at every stage whether the project is valid and whether the product will be useful.
The SDLC is a process that repeats several times and is represented by either a circle or a triangle.
Start at the top corner of the triangle. The Sponsor Goals are the first input

## Initialisation Phase

A Product user is someone who uses a product or service.
The Initialisation Phase starts when a Potential Product User with money (a Sponsor) identifies a need or wish for something new a (Goal).
This Goal may be a totally new product or a change to an existing product to make it easier to use.

## Goals

Sponsors wishes are called Goals.
Sponsors want to:
* use the latest technology
* Improve the technology they use
* reduce the number of staff required to perform a set of tasks
* communicate
* feel intelligent
* be entertained
* make more money by doing less work
* have more free time by doing less work

## Feasibility study

Many companies do a Feasibility study before the project continues to discover whether the project is possible.

## Requirements and Feasibility

The Goals of the Sponsor are translated into Requirements.
A System Analyst will ask the Sponsor questions to define what the true goals are.
The System Analyst will then discuss the goals with
* Project Managers
* Product Managers
* Developers
* Subject Matter Experts (SME).
The team of Experts may decide that the project is not possible.
The System Analyst will then discuss this with the Sponsor to discover if the goals can be reduced or modified.

## Functions

When the initial Requirements have been discovered, then the team of Experts translates the Requirements into Functions that --Chatsami (discuss • contribs) 00:10, 13 November 2014 (UTC)--Chatsami (discuss • contribs) 00:10, 13 November 2014 (UTC)meet the Sponsor's Goals.

## Specification

Specification details all the Functions that must be in the product

## Analysts

Analysts must translate the Goals of the Sponsor into Functions that can be tested.
The SDLC is a process that allows:
* Sponsors
* Analysts
* Managers
* Developers
to analyse and prioritize the Functions needed to fulfil the Goals of the Product user.
This initial description of Product User Requirements is vital to make the project succeed.

## Functions

Functions are system actions caused by Product Users.
Functions must serve the Goals of the Sponsor described in the Requirements.
The Functions of the system lead to the more detailed Specification of the logical and physical system Structure.
'Functions describe WHAT must happen, then designers and developers specify HOW the function happens in the Structure.

## Structures

Structures both support and limit the system.
Structures respond to the environment of the Users, as well as the capabilities of the developers.
Structures provide interfaces, data, workflow, integration, safety, and security. Together, they are tested and delivered to the Users as a Product.
The Users interact with the Product. If the User's Goals are met in the Functions of the Product, the process continues allowing the User to discover new Goals and developers to add new Functions and Structures in the system.

## Products

Product users achieve these Goals by using Products. The Products must satisfy all the requirements
When these Products need an improvement then we return to the Goals of the product user.

## Example 1

* The Product users have cars
* The Product users work for the same company. All the cars are basically the same model.
* The cars are economical (The cars are modern fuel efficient Skodas)
* The Product Users wish to drive to Switzerland for a company sponsored holiday.
* The Product Users wish to add a container above the car to transport skis without loss of performance.
The task is to design and produce a container which will not affect performance beyond certain limits
* define the limits
* Define the deadline (the date when the project must deliver the finished and working product)
* define whether the Product User intends to install the product or whether specialists will install

### The Analyst must ask the Product User the following questions to define the task:

* What constitutes a loss of performance. The engine of the car will perform within the manufacturers specifications. The real performance of the car will not become worse. But:
** The additional container will introduce drag and drag will decrease the speed of the car and increase the quantity of fuel that the engine uses
** The additional weight will decrease the speed of the car and increase the quantity of fuel that the engine uses
* How many skis must the container carry?. Suggest no more pairs of skis than the number of passengers.
* What is the total weight of the skis? ( this affects the performance per litre of fuel)
* What dimensions are the skis ( this affects the dimensions of the container)
* How can the container be attached to the roof of the car?
* When must the container be ready?
--Chatsami (discuss • contribs) 00:11, 13 November 2014 (UTC)=End of lesson Test=
* Why did projects fail before the SDLC? Products were designed without market research.
* What job does an analyst perform? The analyst translates the Sponsor's goals into testable Functions.
* With whom should an analyst discuss the initial requirements? The Sponsor.
* Why do companies run feasibility studies? To determine if the proposed product is capable of being developed into a strong revenue-producing product.
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