Estimating Programming times

[GerryB55 0]

I'm working on a spreadsheet to estimate costs. In the past I have used a 'best guess' for estimating the actual PLC and HMI programming times. Does anyone have any ideas, or know where I might get some, on estimating times based on I/O count, number of modules, tags, number of screens etc? Any ideas gratfully recieved. Thanks in advance

[Chris Elston 78]

I use a rule "1 hour per I/O point". That seems to get me pretty close. Also you can use this spread sheet too. I think you'll like it. It uses minutes to calculate operations. plc_estimate.xlt

[TConnolly 13]

Excellent spreadsheet Chakorules. I use 8 hrs per page for electrical drawings + 1 day. I use a parametric build utility to generate the rough drawing from a spreadsheet, then I detail it. Double the time when its an IEC drawing. Each specialty symbol on the drawings adds 2 hours to the estimate. For programming: I use 1 day/discrete IO card upto 16 points, 2 days for 32 point cards. Analog entirely depends upon the application and my own experience. I swag it on the HMI, I haven't really developed a method there except to rely on my experience, sometime I take a bath on those.

[PdL 71]

Whatever you estimate on hours, if you think you got it all - multiply times 2. In the end it proves to work out that way.

[gravitar 3]

I've found that this formula works well on estimating materials cost, too :)

[LarryE77 0]

On ‎6‎/‎17‎/‎2005 at 0:18 PM, Chris Elston said:

I use a rule "1 hour per I/O point". That seems to get me pretty close. Also you can use this spread sheet too. I think you'll like it. It uses minutes to calculate operations. plc_estimate.xlt

How can I get a copy of the plc_estimate.xlt ?