Prison Population Projections 2014 – 2020 
Figure B1: Key Components of the prisons projections modelling system 
Impacts of 
Legislation 
and Process 
Change
Historical 
Defendants 
Proceeded 
Against
Historical 
Prison 
Receptions
Historical 
Time 
Served Data
Demand 
Projections 
Model
Future Defendants 
Proceeded Against 
by Offence Type
Prison Projections
Prison 
Population 
Stock-Flow 
Model
Future Offenders 
Disposed of by 
Disposal, Age and 
Gender
Future Offenders 
with a Custodial 
Convictions by Age 
and Gender
Historical 
Age and 
Gender Data
Historical 
Court 
Disposals 
Data
Historical 
Court Route 
Data
Impacts of 
Legislation 
and Process 
Changed
Input
Model
Output
Key
Courts and 
Sentencing 
Module
1
2
3
Impacts of 
Legislation 
and Process 
Change
Impacts of 
Legislation 
and Process 
Change
Historical 
Defendants 
Proceeded 
Against
Historical 
Defendants 
Proceeded 
Against
Historical 
Prison 
Receptions
Historical 
Prison 
Receptions
Historical 
Time 
Served Data
Historical 
Time 
Served Data
Demand 
Projections 
Model
Demand 
Projections 
Model
Future Defendants 
Proceeded Against 
by Offence Type
Future Defendants 
Proceeded Against 
by Offence Type
Prison Projections
Prison Projections
Prison 
Population 
Stock-Flow 
Model
Prison 
Population 
Stock-Flow 
Model
Future Offenders 
Disposed of by 
Disposal, Age and 
Gender
Future Offenders 
Disposed of by 
Disposal, Age and 
Gender
Future Offenders 
with a Custodial 
Convictions by Age 
and Gender
Future Offenders 
with a Custodial 
Convictions by Age 
and Gender
Historical 
Age and 
Gender Data
Historical 
Court 
Disposals 
Data
Historical 
Court Route 
Data
Impacts of 
Legislation 
and Process 
Changed
Impacts of 
Legislation 
and Process 
Changed
Input
Model
Model
OutputOutput
Key
Courts and 
Sentencing 
Module
Courts and 
Sentencing 
Module
1
1
2
2
3
3
 
 
 
 
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