Some television programmes take a long time to make.
If you want to show the most hidden human behaviour within our communities, you're going to need a lot of patience.
After the Baby P crisis, the BBC commissioners asked my production team to make a new documentary about child protection services.
Our crews would follow individual social workers and families over months to see how the social workers tried to make situations better for children at risk.
Shaun and his baby
Even with good historical relations, the sensitivity was such that took us over a year to agree a modus operandi with the council.
The crux, we all agreed from the outset was, the welfare of any child involved has to come first. The details of what that means in specific situations is complex.
Then we started filming.
It took months of hard work to try and persuade people to take part to show the real nitty gritty of the actual cases with families.
In the meantime all we could do was film the more straightforward parts that we knew would provide the 'glue' to make all the programmes piece together, like shots of the city, simple meetings amongst the social workers.
What was key was that everyone got used to us being around with our cameras, so when real action happened later we could film it, unhindered.
How do you even ask a family who are probably in the worst place of their lives whether they would like to consider taking part in a television programme?
It's impossible to build up trust and understanding when you first contact someone.
When we got to the point of spending time chatting to people face to face in their homes, it became somewhat easier.
Slowly with patience and consideration we got somewhere, but I can never imagine a more difficult ask for members of the public.
We were able to offer a very different way of taking part - a system called rolling consent.
That meant anyone being filmed could choose to pull the plug and decide not to continue at any point in the process - after the first day, after six months or after they had seen the finished film.
We quickly learned that the only way to progress was to be a fully open book - to be honest and clear.
We showed everyone who took part the final film and agreed to change anything factually inaccurate and listen carefully to other objections (which didn't include anyone's hair looking bad on a particular day!).
Slowly we found people did have reasons for wanting to take part.
Some people wanted to pass on advice to others in similar life situations. As Shaun, one of the fathers says in the finished programme "appreciate it, love your children best. Don't go my way - I made the biggest mistake. I've lost my children and I try and fight for them - you know stay strong, don't give up."
For some our presence acted as further encouragement to make progress at home. For others who were battling with social workers, they wanted their side of events faithfully recorded.
So eventually we gained access into people's lives and started to film with a small crew of two or three people.
The stunning aspect of observational filming over a long period of time is the course of people's stories changes in ways that you could never imagine.
We never could have predicted that whole families who appeared to be united would fall apart in a matter of weeks. As John Lennon stated: "Life's what happens when you're busy making other plans...".
As we got more involved with the people's lives, we got to understand what a privileged position we occupied.
Social worker Annie
We were able to speak to the families in confidence (as long as it what they said did not affect the welfare of their children). At the same time we would hear the inside track from the social workers' point of view.
When some of the hard decisions needed to be made about the future of the children, we found ourselves overcome with emotion and often reeling for months after.
Surprisingly the social workers themselves were also deeply affected by certain cases that they became ensconced in, despite their extensive training to maintain professional boundaries with families. Somehow I found that reassuring.
This series will live with all who took part for the rest of their lives.
After three years of work we are finally able to show three hours of television that gives an insight into a world many of us never get to see, but one that continues around us in all our neighbourhoods.
Sacha Mirzoeff is the series producer of Protecting Our Children.
For further programme times, please visit the episode guide.
If you, or someone you know, have been affected by the issues raised in this programme, you can visit the information and support page (available until 23 March).
Comments made by writers on the BBC TV blog are their own opinions and not necessarily those of the BBC.