They really work efficiently.. Even big heads of foreign countries had praise their work.. So they deserve it.

Efficiency earns respect

PM Modi nominated them in earlier series of responsibility for clean India campaign. 

Yes Modi nominated them along with others. Kapil Sharma of "Comedy Nights " is one of them to spread Swachh Bharat  Campaign.

I have never ever have opportunity to see how these dabbawalas work, as I never ever posted there, but four years back during my posting at Bhilai, I have seen the small scale daba industries with good qualitative foods offerings.

Dabbawallas of Mumbai are famous all over the world. Because their way of functioning and promptness even attracted the Management Gurus. They were recognized as the epitome of Excellence In Time Management.

They are well known, and their actions are emulated by quite a few, but I personally never experience it read from different sources as they are excellent in TQM and JIT.

There are many websites about these Dabbawalas. It is a show case of efficient Management.

They are in great in numbers but the way they manage time with simple symbols has been talking point in many management studies.

Simply put the adjective "Iconic" is very apt for these Dabbawalas.