"Can tight" is a familiar term for grocery operators that indicates a shelf is fully ready for a consumer.  Products are fronted, and as fully stocked as available inventory will provide.  Shelves stocked "can tight" are assumed to be set correctly.
 
This practice was identified as being responsible for hiding out-of-stocks, as holes were routinely "faced over".  It turns out that leaving those holes open might help slightly in combating those out of stocks.  However, what is definitely true is that product that looses shelf space has a difficult time finding its way back.  No amount of standing in front of the shelf divining what might be out of place, short faced, or void is very productive.
 
Staring at a shelf set, thinking about the plan that is supposed to be in place and identifying and understanding the differences from that plan is a tough, tough assignment.  Even with aids such as inference generated "alerts" and no-scan reports the process is frustratingly difficult.  DSR technology frequently generates false positives or, even more frequently, fails to report real issues.  Let's look at a quick example:

 

 

This picture of a modular (viewed through the ShelfSnap application) is what continuity merchandisers face every day.  Merchandisers typically visit 2-5 stores and review 2-15 categories in each store.  Usually, they might have 1-2 tasks to accomplish (cut in an item, build a display) along with checking that the shelves are "can tight and right." 
 
In this case the merchandiser's eye would naturally be drawn to the out-of-stock in the second position on shelf 1 in the second segment.  It might also be drawn to shelves 1 and 2 in segment three where products could use a good face up.  But the rest of the set "is can tight and looks right". 
 
In this case the continuity merchandiser had all most of the modern tools that could be brought to task including:

 

• Mobility Solution and PDA.

Even with these tools the task of separating the real issues from the false positives is impossible.  The hurdle the merchandiser is facing is simple human physiology.  According to Dr. Wolf, a Harvard Ophthalmology Professor and chair of the school's Visual Attention Lab, there are confounding operations needed to complete this comparison which puts a tremendous strain on mere mortals.  One of those hurdles, called the prevalence error, affects the merchandiser in two ways.  First, the eye is drawn toward the obvious issues, the out-of-stock in this case and away from the rest of the shelf.  Further, the brain "expects" to see a "can tight" shelf and once it sees that it has a hard time seeing beyond that fact into the content of the shelf.   In other words the job as defined, given the tools above is impossible to do.
 
So, how far from the planned Modular was this particular set, after the continuity merchandiser left the store?  If we define compliance, as we ought to, in terms of the correct products, in the correct spots with the correct facings, than the average store in this study has been compromised by almost 60%!
 
ShelfSnap carried the investigation a bit further comparing actual compliance in stores that received a normal amount of store servicing, against stores that received an extraordinary amount of additional continuity merchandising staffed by professionals engaged by the manufacturer who dominated the category.  These resources were directed by a mobility solution driven by daily sales information.  After a brief shake out period, where the continuity resources seemed to be having an impact (building off a very non-compliant base), compliance slipped and both level and trend of plan compromise became identical in both panels.  In other works, incremental continuity merchandising by itself had absolutely no impact on plan compliance.   When ShelfSnap added in SnapTask Directed Merchandising, picture based analysis about which products and positions need attention, the results turned positive very dramatically.  How dramatic?  Double digits - a 15% sales increase!