I need a PHP coder/developer (long term)

General information for the business: We have an online job booking and workflow processing application that needs upgrading/developing.
Kind of development: Customization of existing program
Description of requirements/functionality: Please see extra notes below
Specific technologies required: PHP, javascript and Mysql
Extra notes: Hi,

We have an online job booking and workflow processing application. We need a php developer to continue the development. We have currently just launched version 2 of our application and are planning version 2.1 onwards already. The coding method currently employed is standard PHP. Our current developer is over worked and exhausted. We need the help of a competent and experienced coder. Our current developer will be available to support the new coder.

This is a very long term relationship as we are also planning the modifications necessary to launch into other business sectors, both in the UK and abroad already.

We have one upgrade module that we can use as a test piece to see if we can work well together, involving google maps and the route planning of a vehicle(s) and driver(s).

If this is of interest to you, please let me know.

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The Specification

Each job the driver will have to perform has a standard time allowed for completion, along with its' cost to the customer.

Safety margins (usually a percentage) configured by the user, are added to each job and travel times, to allow for unforeseen problems.

I want to start from my home/home base at SS7 5TE, leaving at 9am
I want to return to my home/home base at SS7 5TE, by 6pm

My jobs are at SS9 3BH, BT7 5RT, CO2 6FD, CM3 1AA, BS3 8TY. Obviously, we will use full addresses. Using google maps, we need to find the nearest job to SS7 5TE. It is CM3 1AA! Then we need to find the nearest of the remaining jobs to CM3 1AA. It is BT7 5RT, and so on to get this:

Start SS7 5TE 09:00:00
#1 CM3 1AA
#2 BT7 5RT
#3 CO2 6FD
#4 SS9 3BH
#5 BS3 8TY
Finish SS7 5TE 18:00:00

Now we need to loop through google maps to produce and display the optimum routes for the following sceanarios.

Scenario #1 - Assume the customers are available any time of the day.

Scenario #2 - Assuming the customer for job#2 is not available until after 1pm.

Scenario #3 - Assume there are 3 drivers working in their business. They may all leave/return to their main base daily. Alternatively, they may all start from (and return to) their individual home addresses. Say they had 30 jobs booked, they would need three optimised routes, one for each driver.

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