I'm not in retail but I do know the following that given the rise of online and Amazon in particular - a department store can only really sell based on following
Price, service, quality or 'an experience'
They aren't going to win on price and at the moment don't seem to be offering the others either. Now I love a good department store- big fan of Ka de we in Germany and we had several fantastic ones when we lived in Copenhagen- here's my tips from those to invigorate JL
Big stores
Don't bother with electrical , sofas, beds etc- you won't win on price and it's not an experience and will cause more hassles with 'faulty goods' and deliveries etc
Bring back a good half floor dedicated to crafts-good fabric section, dried flowers, interiors type stuff, jewellery making stuff, artist supplies - have an artist in residence every week, dressmaker, potter, jewellery maker-whatever!
Split your stores up and have a great 'special occasions' section - mother of bride, bridal, bridesmaids , Xmas dos, christenings - shoes, headwear, underwear etc- all together
Have a great baby and under 5 section- again all together. Good quality toys, buggies, clothes , shoes, books, car seats, high chairs etc - some kind of do this - but not that well.
Have a great cookware section and plenty of showcasing by bakers to chefs in different themes- Moroccan day, Italian day, Indian day etc
Bring in a lovely ground floor circular wine bar- well lit , ka de we have lovely ones and link them to a really good top end bottled and dried goods deli
Give a half floor to an indoor 'artisan ' market - for small spaces for local craftspeople- jewellery, hats, potters, biscuit makers, kids clothes- whatever - section it off so it looks like a market and make sure quality is kept high .
For Christ sake then market all of above- make it feel special - M&S run rings around you on marketing.
From another angle - open a few JL minis in upmarket towns where there isn't a suitable space for a big JL or you want to test the water. Make them specialist and niche- do a JL special occasions or a JL- baby etc or a JL - gifts - wherever you think there is a retail gap in that town
Your stores are often so big I go in with the idea to get xyz (specific) but are often so all over the shop that I lose the will- niche works!!