Spread Sheet

What is Mcrosoft Excel?

Microsoft Excel is a commercial spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications. It has been a very widely applied spreadsheet for these platforms, especially since version 5 in 1993, and it has almost completely replaced Lotus 1-2-3 as the industry standard for spreadsheets. Excel forms part of Microsoft Office. The current versions are 2010 for Microsoft Windows and 2011 for Mac OS X.Microsoft Excel provides a grid interface to organize nearly any type of information.  The power of Excel lies in its flexibility to define the layout and structure of the information you want to manage.  Basic tasks require no special training, and Excel allows you to work with text, numbers, and date information in a relatively open and unstructured way.  Nearly 30 years after its initial introduction, Excel remains the world’s leading spreadsheet software.

Uses of Microsoft excel:

Spreadsheets are often used to store financial data. Formulas and functions that are used on this type of data include:

• Performing basic mathematical operations such as summing columns and rows of figures.
• Finding values such as profit or loss.
• Calculating repayment plans for loans or mortgages.
• Finding the average, maximum, or minimum values in a specified range of data.

Other common operations that Excel can be used for include:

• graphing or charting data to assist users in identifying data trends.
• sorting and filtering data to find specific information.

The information garnered in a spreadsheet can easily be incorporated into electronic presentations, web pages, or printed off in report form.

What Are Spreadsheet models?

A computer spreadsheet program allows you to create, edit and maintain a spreadsheet (or worksheet) full of data. Spreadsheets allow you to make budgets, invoices and similar documents. They're used heavily in the business and financial sectors. Spreadsheet models allow most of the preparation work to be done for you.

Spreadsheet models exist for a variety of different common purposes, such as the budget of an event or the organization of a payroll.Common uses for spreadsheet models include getting budget estimates or inputting different sets of data to experiment with different financial outcomes.

Spreadsheet models usually come in a certain file format. Microsoft Excel has a large spreadsheet program; other options include Apple Numbers, Google Docs (which reads many formats) and Lotus Symphony.

Advantages of models:

1. Formula can be used to instantly to recalculate totals. 
2. The information can be presented in different ways.
3. You can carry out what if investigations.

Using a spreadsheet you can see all the data at once and when you change any data all computations can be instantaneously updated with the change.

It is a place where you can organize your information. Also if you are using numbers, you can input eqautions to help run those numbers (ex. Excel).

you don't really have to any of the work because if you are finding out sums(working out) you can just drag it and it will bring up all of the other answers for you.

System Life Cycle

The Systems development life cycle (SDLC), or Software development process insystems engineering, information systems and software engineering, is a process of creating or altering information systems, and the models and methodologies that people use to develop these systems. In software engineering, the SDLC concept underpins many kinds ofsoftware development methodologies. These methodologies form the framework for planning and controlling the creation of an information system:^[1] the software development process.

The SDLC is a process used by a systems analyst to develop an information system, training, and user (stakeholder) ownership. The SDLC aims to produce a high quality system that meets or exceeds customer expectations, reaches completion within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, and is inexpensive to maintain and cost-effective to enhance.^[2] Computer systems are complex and often (especially with the recent rise of service-oriented architecture) link multiple traditional systems potentially supplied by different software vendors. To manage this level of complexity, a number of SDLC models or methodologies have been created, such as "waterfall"; "spiral"; "Agile software development"; "rapid prototyping"; "incremental"; and "synchronize and stabilize".^[3]

SDLC models can be described along spectrum of agile to iterative to sequential. Agile methodologies, such as XP and Scrum, focus on lightweight processes which allow for rapid changes along the development cycle. Iterative methodologies, such as Rational Unified Process and dynamic systems development method, focus on limited project scope and expanding or improving products by multiple iterations. Sequential or big-design-up-front (BDUF) models, such as Waterfall, focus on complete and correct planning to guide large projects and risks to successful and predictable results^{[citation needed]}. Other models, such as Anamorphic Development, tend to focus on a form of development that is guided by project scope and adaptive iterations of feature development.

In project management a project can be defined both with a project life cycle (PLC) and an SDLC, during which slightly different activities occur. According to Taylor (2004) "the project life cycle encompasses all the activities of the project, while the systems development life cycle focuses on realizing the product requirements".^[4] SDLC (systems development life cycle) is used during the development of an IT project, it describes the different stages involved in the project from the drawing board, through the completion of the project.

Air Conditiong

Air conditioning is the removal of heat from indoor air for thermal comfort.
In another sense, the term can refer to any form of cooling, heating, ventilation, or disinfection that modifies the condition of air.^[1] An air conditioner (often referred to as AC or air con.) is an appliance, system, or machine designed to change the air temperature and humidity within an area (used for cooling as well as heating depending on the air properties at a given time), typically using a refrigeration cycle but sometimes using evaporation, commonly for comfort cooling in buildings and motor vehicles.

An air conditioner (often referred to as AC) is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle. In construction, a complete system of heating, ventilation and air conditioning is referred to as "HVAC".