diff --git a/src/sourcery/bin_m.f90 b/src/sourcery/bin_m.f90
index cd533d7f..edd396f1 100644
--- a/src/sourcery/bin_m.f90
+++ b/src/sourcery/bin_m.f90
@@ -26,19 +26,17 @@ elemental module function construct(num_items, num_bins, bin_number) result(bin)
 
   interface
 
-    elemental module function first(self, bin_number) result(first_item_number)
+    elemental module function first(self) result(first_item_number)
       !! the result is the first item number associated with the given bin
       implicit none
       class(bin_t), intent(in) :: self
-      integer, intent(in) :: bin_number
       integer first_item_number
     end function
 
-    elemental module function last(self, bin_number) result(last_item_number)
+    elemental module function last(self) result(last_item_number)
       !! the result is the last item number associated with the given bin
       implicit none
       class(bin_t), intent(in) :: self
-      integer, intent(in) :: bin_number
       integer last_item_number
     end function
 
diff --git a/src/sourcery/data_partition_m.f90 b/src/sourcery/data_partition_m.f90
index a310506e..70f3dd73 100644
--- a/src/sourcery/data_partition_m.f90
+++ b/src/sourcery/data_partition_m.f90
@@ -18,8 +18,6 @@ module data_partition_m
     generic :: gather => gather_real32_2D_array, gather_real64_2D_array,  gather_real32_1D_array, gather_real64_1D_array
   end type
 
-  integer, allocatable :: first_datum(:), last_datum(:)
-
   interface
 
     module subroutine define_partitions(cardinality)
diff --git a/src/sourcery/data_partition_s.f90 b/src/sourcery/data_partition_s.f90
index 65078141..bafdc0aa 100644
--- a/src/sourcery/data_partition_s.f90
+++ b/src/sourcery/data_partition_s.f90
@@ -1,51 +1,26 @@
 submodule(data_partition_m) data_partition_s
   use assert_m, only : assert
+  use bin_m, only : bin_t
   implicit none
 
   logical, parameter :: verbose=.false.
+  type(bin_t), allocatable :: bin(:)
 
 contains
 
   module procedure define_partitions
-
-    if (allocated(first_datum)) deallocate(first_datum)
-    if (allocated(last_datum)) deallocate(last_datum)
-
-    associate( ni => num_images() )
-
-      call assert( ni<=cardinality, "sufficient data for distribution across images", cardinality)
-
-      allocate(first_datum(ni), last_datum(ni))
-
-      block
-        integer i, image
-        do image=1,ni
-          associate( remainder => mod(cardinality, ni), quotient => cardinality/ni )
-            first_datum(image) = sum([(quotient+overflow(i, remainder), i=1, image-1)]) + 1
-            last_datum(image) = first_datum(image) + quotient + overflow(image, remainder) - 1
-          end associate
-        end do
-      end block
-    end associate
-
-  contains
-
-    pure function overflow(im, excess) result(extra_datum)
-      integer, intent(in) :: im, excess
-      integer extra_datum
-      extra_datum= merge(1,0,im<=excess)
-    end function
-
+    integer image
+    bin = [( bin_t(num_items=cardinality, num_bins=num_images(), bin_number=image), image=1,num_images() )]
   end procedure
 
   module procedure first
-    call assert( allocated(first_datum), "allocated(first_datum)")
-    first_index= first_datum( image_number )
+    call assert( allocated(bin), "data_partition_s(first): allocated(bin)")
+    first_index = bin(image_number)%first()
   end procedure
 
   module procedure last
-    call assert( allocated(last_datum), "allocated(last_datum)")
-    last_index = last_datum( image_number )
+    call assert( allocated(bin), "data_partition_s(last): allocated(bin)")
+    last_index = bin(image_number)%last()
   end procedure
 
   module procedure gather_real32_1D_array
diff --git a/test/bin_test.f90 b/test/bin_test.f90
index 38be4e30..2ae7f74d 100644
--- a/test/bin_test.f90
+++ b/test/bin_test.f90
@@ -51,7 +51,7 @@ function verify_block_partitioning() result(test_passes)
     integer b
 
     bins = [( bin_t(num_items=n_items, num_bins=n_bins, bin_number=b), b = 1,n_bins )]
-    associate(in_bin => [(bins(b)%last(b) - bins(b)%first(b) + 1, b = 1, n_bins)])
+    associate(in_bin => [(bins(b)%last() - bins(b)%first() + 1, b = 1, n_bins)])
       associate(remainder => mod(n_items, n_bins), items_per_bin => n_items/n_bins)
         test_passes = all([(in_bin(1:remainder) == items_per_bin + 1)]) .and. all([(in_bin(remainder+1:) == items_per_bin)])
       end associate
@@ -69,7 +69,7 @@ function verify_all_items_partitioned() result(test_passes)
     integer b
 
     bins = [( bin_t(num_items=n_items, num_bins=n_bins, bin_number=b), b = 1,n_bins )]
-    test_passes = sum([(bins(b)%last(b) - bins(b)%first(b) + 1, b = 1, n_bins)]) == n_items
+    test_passes = sum([(bins(b)%last() - bins(b)%first() + 1, b = 1, n_bins)]) == n_items
 
   end function