diff --git a/app/BWT.py b/app/BWT.py
index 469b508..0decc7d 100644
--- a/app/BWT.py
+++ b/app/BWT.py
@@ -1,6 +1,6 @@
 from app.settings import *
 import csv, glob
-from multiprocessing import Pool
+from concurrent.futures import ThreadPoolExecutor, as_completed
 import time
 import statistics
 from Bio import SeqIO, Seq
@@ -379,6 +379,23 @@ def get_aligned(self):
 		output_tab=self.output_tab
 		subprocess.run(f"samtools idxstats {input_bam} > {output_tab}", shell=True, check=True)
 
+	def preload_alignments(self):
+		"""
+		Parse tab-delimited file into dictionary for mapped reads
+		"""
+		self.alignments = {}
+		with open(self.output_tab_sequences, 'r') as csvfile:
+			reader = csv.reader(csvfile, delimiter='\t', quotechar='|')
+			for row in reader:
+				self.alignments.setdefault(row[2], []).append({
+						"qname": str(row[0]),
+						"flag": str(row[1]),
+						"rname": str(row[2]),
+						"pos": str(row[3]),
+						"mapq": str(row[4]),
+						"mrnm": str(row[5])
+						})
+				
 	def get_qname_rname_sequence(self):
 		"""
 		MAPQ (mapping quality - describes the uniqueness of the alignment, 0=non-unique, >10 probably unique) | awk '$5 > 0'
@@ -394,6 +411,7 @@ def get_qname_rname_sequence(self):
 		input_bam=self.sorted_bam_sorted_file_length_100
 		output_tab=self.output_tab_sequences
 		subprocess.run(f"samtools view --threads {threads} {input_bam} | cut -f 1,2,3,4,5,7 | sort -s -n -k 1,1 > {output_tab}", shell=True, check=True)
+		self.preload_alignments()
 
 	def get_coverage(self):
 		"""
@@ -642,23 +660,8 @@ def get_baits_details(self):
 		return baits
 
 	def get_alignments(self, hit_id, ref_len=0):
-		"""
-		Parse tab-delimited file into dictionary for mapped reads
-		"""
-		sequences = []
-		with open(self.output_tab_sequences, 'r') as csvfile:
-			reader = csv.reader(csvfile, delimiter='\t', quotechar='|')
-			for row in reader:
-				if hit_id == row[2]:
-					sequences.append({
-						"qname": str(row[0]),
-						"flag": str(row[1]),
-						"rname": str(row[2]),
-						"pos": str(row[3]),
-						"mapq": str(row[4]),
-						"mrnm": str(row[5])
-						})
-			return sequences
+		sequences = self.alignments.get(hit_id, [])
+		return sequences
 
 	def get_coverage_details(self, hit_id):
 		"""
@@ -833,7 +836,7 @@ def probes_stats(self, baits_card):
 					reads_to_baits[j] = [t]
 				else:
 					if t not in reads_to_baits[j]:
-					 reads_to_baits[j].append(t)
+						reads_to_baits[j].append(t)
 
 		with open(self.reads_mapping_data_json, "w") as outfile2:
 			json.dump(reads_to_baits, outfile2)
@@ -1183,10 +1186,10 @@ def summary(self, alignment_hit, models, variants, baits, reads, models_by_acces
 					if trailing_bases:
 						consensus_sequence_protein = consensus_sequence_protein[:-1]
 
-					if alignment_hit in read_coverage.keys():
+					if read_coverage.get(alignment_hit):
 						read_coverage_depth = read_coverage[alignment_hit]["depth"]
 
-					if alignment_hit in mutation.keys():
+					if mutation.get(alignment_hit):
 						snps = "; ".join(mutation[alignment_hit])
 
 				except Exception as e:
@@ -1339,9 +1342,13 @@ def get_summary(self):
 		for alignment_hit in reads.keys():
 			jobs.append((alignment_hit, models, variants, baits, reads, models_by_accession,mutation,read_coverage,consensus_sequence,))
 
-		with Pool(processes=self.threads) as p:
-			results = p.map_async(self.jobs, jobs)
-			summary = results.get()
+		with ThreadPoolExecutor(max_workers=self.threads) as executor:
+			futures = []
+			summary = []
+			for job in jobs:
+				futures.append(executor.submit(self.jobs, job))
+			for future in as_completed(futures):
+				summary.append(future.result())
 
 		# logger.info("Time: {}".format( format(time.time() - t0, '.3f')))
 		# write json