Legacy information system Essay

An Probe On The Impact Of An Integrated System To Overhaul A Legacy Information System ( LIS ) . Case Study Of ABBC Ltd. ( UK )

Current Situation

The intent of this research as stated in the undertaking proposal and initial undertaking study is to seek to supply an analytic reappraisal of the common LIS modernization attacks and to suggest a suited option for ABBC ltd who presently seeks thoughts for modernizing their system. At this phase the undertaking is chiefly focused on developing an apprehension of what Legacy Information Systems are, what schemes are available to ease ascents or modernizations, and how concerns can utilize them to simplify their operations and systems.

To get down with it must be said that the first three aims seemed to be the most simple ab initio, but they turned the undertaking on its caput and forced a re-think of where to truly get down. The subject proved to be really broad and encompassed so many strands, that the initial research for this became unmanageable. However these aims have been met and the pacing of the research has been changed to concentrate on why ABBC Ltd, need an upgraded system. This has culminated in the apprehension of the different attacks or schemes proffered in the literature research.

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This displacement in focal point allows a better apprehension of what the undertaking enterprise truly is.

Problem Areas:

The jobs encountered so far are really minimum, although the really chief one is the eternal hunt for indifferent information. The probe is a gigantic undertaking with waies taking to the assorted transmutation attacks proposed, and, I am happening it hard to choose for one peculiar attack for the system upgrade as they all have their advantages and disadvantages.

Keywork During The Following Time period

As was mentioned before the undertaking has been divided into assorted stages and so far merely two of the seven stages have been accomplished. The staying five will be carried out over the following period. These are:

  • Design solutions and proficient architecture – the major activity during the design stage is the development of the new system design papers which outlines the functional and proficient demands of the system. It besides includes user interface designs, specific map definitions and overall system architecture.

  • Design informations migration scheme – during this stage a program will be designed for the migration of bing informations on the old system onto the new system.
  • Develop new system stage – consultative function – the development procedure brings the new system to life. The new system designed proposal serves as the design for the building of the system. It provides a route map detailing precisely which pieces will be built, in which order, and how each bed of the solution can be laid over the base. Once the functional faculties are complete and unit tested, integrating proving Begins. The end of integrating testing is to guarantee that the completed faculties have the proper inter-operability required both internally and externally to the system.

  • Propose proving stage – consultative function – This is the recommended testing performed on a package subsystem or a completed package physique composed of faculties that encompasses package functionality and exercises the interfaces between package faculties including mistake handling. It is performed either by examiners or package developers, and non the research worker.
  • Propose execution stage – consultative function – The execution stage begins with developing the company squad on the work processes, constellation, and usage applications that were developed. The execution undertakings cover system installing, apparatus, and the passage into production. This will besides include the preparation stage.

Benefits Of The Books And Other Materials Used For The Literature Review

The purpose of carry oning a literature hunt is to develop an apprehension of Legacy Information Systems ( LIS ) and to ease the hunt for similar constructs and the pursuit for instance survey stuffs.

Some of the books were rather proficient in contents but non hard to understand. Once an apprehension of the whole construct had been developed the proficient slang did non look excessively foreign and re-reading of these stuffs allowed for a deeper apprehension of the capable affair better.The different transmutation solutions or attacks were borne out by writers like Patel and O’Callaghan who wrote “while it has become apparent that administrations need to use and, are using evolutionary attacks to develop and pull off their package systems ( Patel 2003 ) , the presence of LIS in this regard remains an unfastened challenge ( O’Callaghan 1999 ) for bulk of concern organizations” , which is really true. This fact has a knock-on consequence in that more and more concerns are now seeking ways and means to alter their LISs.The findings of this literature hunt provided the background and underpinning cognition as to how to better or upgrade old systems, and what this move can make for a concern.

It besides confirms the fact that although this country of research is reasonably recent there are tonss of stuffs available on the subject.

Chapter 1 – Introduction


This chapter is a brief sum-up on the stairss involved in set abouting a undertaking on the modernization of a bequest system, and how the purpose of upgrading or planing something new wholly will impact a kitchen ware and utensils retail merchant, ABBC Ltd.


Computer systems have a really short life-expectancy due to the rapid alteration of proficient developments, administrations have to often upgrade their systems and, this is the ground why the direction of ABBC Ltd has requested for a undertaking like this: an ascent to their Legacy Systems.There are frequently tonss of jobs with Legacy Systems, for these are systems which have been written for rather a considerable length of clip and have been upgraded clip and clip again.This can do the system really fragile.Rebuilding the system once more from abrasion would be a good thought but because the system is operational direction seems to be loath to supply the financess, so, planing a simple and suited ascent seems to be the appropriate option.It is non ever necessary for every section in an administration to hold their hardware or package upgraded.Different people do different occupations and, hence, have different demands.

Person who is making really proficient work for illustration, heavy artworks, or multimedia work may necessitate a really powerful computing machine to make his occupation decently.The intent of this research as stated is to seek to supply an analytic reappraisal of the common LIS modernization attacks and to suggest a suited option for ABBC ltd who presently seeks thoughts for modernizing their system. Modernization involves more extended alterations than care, but, conserves a important part of the bing system. These alterations frequently include system restructuring, of import functional sweetenings or new package properties ( Seacord et al 2002 ) .

Another of import factor is, to besides seek to supply a comparative reappraisal of the common attacks for overhauling bequest systems, expression at the current IT substructure of ABBC ltd, propose and design an integrated computing machine system taking into consideration the bing restrictions of the current systems. The new system will be designed on the footing of dependability, flexibleness, compatibility, cost, security and an unsophisticated execution procedure which enhances efficiency and efficaciousness.

The LIS Challenge

Evolving and incorporating Information Systems ( IS ) in line with altering concern demands requires considerable sum of attempt and cost, and the effectual transmutation of its Legacy Information Systems, ( LIS ) , in this regard remains an unfastened challenge ( O’Callaghan 1999 ) . LIS are bing package systems that deliver concern value to administrations, but over clip have become progressively hard to pull off and germinate in line with concern demands ( Bennett 1995 ; O’Callaghan 1999 ) . The tremendous nature of the undertaking is evident in industry figures ; it is estimated that for every ?100k spent in an administration ‘s systems development budget, some ?50k is spent on modifying bing systems to cover with concern alteration ( Gibbs 1994 ; Raviart 2001 ; Standish 2003 ) . Furthermore, for every ?1 spent on development, ?10 is spent on integrating with bing systems.

Overall, the figures in seeking to pull off and keep LIS costs administrations worldwide at least ?150 billion per twelvemonth ( synthesizing figures from Standish and Gartner ) . As a consequence, the transmutation of these systems, poses several challenges to concern administrationLegacy information system ( LIS ) can be adequately defined in short as information systems that are alteration and alteration resistant, although they typically form the base of the information flow in any administration and without them the systems may hold serious concern impact on the administration. The rapid growing in computing machine use in the past decennary has resulted in some big, complex systems that have evolved to a province where they significantly resist farther alteration and alteration. These systems, most frequently than, non pose considerable jobs such as being slow and inflexible, stray, non-extensible, and, deficiency openness which are all factors that affect the smooth running or operations of the system, and may be termed as mission-critical, for if any one of these systems stops working the concern may crunch to hold.

As stated earlier LIS forms the anchor of the information flow within an administration and is the chief factor responsible for consolidating information within a concern, so it can non be easy done off with, or, replaced. A failure or dislocation of one of these systems can hold a serious and ruinous impact on the concern. As it is, they presently pose troubles and challenges to the concern as in this instance of ABBC Ltd. Among these are:

  • These systems are normally run on obsolete hardware which is really slow and, dearly-won to keep.
  • Care of package is by and large really expensive as following mistakes is dearly-won, clip consuming, and, about impossible due to miss of certification and constantly, a deficiency of apprehension of the internal workings of the system.
  • Integration of attempts are by and large hampered by the absence of clean interfaces
  • Bequest systems are really hard if non impossible to spread out.

There are several solutions that have been put frontward to work out the under-lying jobs of these types of systems. These solutions fall by and large into three classs viz. ( a ) renovation which is the re-writing of bing bequest applications, ( B ) wrapper, which is fundamentally wrapping the bing constituent in a new, more accessible package constituent, and ( C ) migration, which involves traveling the LIS to a more flexible environment, while retaining the original system ‘s informations and maps.

Given the graduated table, complexness, and hazard of failure in LIS undertakings, a well defined, easy implemented, and, elaborate methodological analysis is indispensable for the undertaking ‘s success. However, few comprehensive LIS migration methodological analysiss are available, and there are several general attacks to be agreed on. Existing attacks are either excessively high-levelled, or, have yet to be applied in pattern.

Although a partial solution such as wrapper is widely adopted, such solution is frequently short-run and, can really perplex LIS care and direction over the long term. On the other manus, renovation attacks tend to be excessively hazardous and dearly-won for most organisations. The migration methodological analysis is normally seen as a sound and, the best scheme for postulating with LISs.

The ABBC LTD LIS Challenge

ABBC Ltd is a wholesale/retail concern located in the South of London which deals with Kitchen stuffs & A ; utensils. Examples of stock handled by ABBC include cookers, sinks, microwave, electric refrigerators, kitchen edifice stuffs, electrical merchandises for kitchens and insularity of kitchen. ABBC LTD was established in 1979, with the intent of supplying the Kitchen development trade of a little part with supplies.

It has staff strength of one hundred and twenty in its three subdivisions. The company has an mean annual turnover of about 60 five million lbs.The increased size and physical distribution of ABBC ‘s operation overloaded the original manual patterns. In peculiar, ABBC began to see troubles in its accounting operations, and, keeping accurate stock records. These troubles caused ABBC ‘s direction squad to seek professional aid which advised ABBC to present machine-controlled support for its concern. Functions correspond to physical sites which procedure information. Data flowing between the sites comprises electronic informations ( the ‘warehouse stock list ‘ for illustration ) , physical entities ( such as ‘stock ‘ ) , and manual communications ( ‘stock enquiry ‘ ) .

A individual warehouse is located centrally to the mercantile establishments. Its location is critical for supplying an effectual distribution channel to assorted mercantile establishments. All providers of ABBC deliver entirely to the cardinal warehouse, from where stock is transferred to mercantile establishments. Head office, which is responsible for ABBC ‘s operation and direction, is located nearby the warehouse.Head office is responsible for five maps:1. Histories receivable – Mercantile establishments may offer sweeping clients recognition, and so head office trades with these histories. This involves debiting histories for recognition gross revenues, crediting histories when payments are received, and, bring forthing history statements and despatching bills.

2. Histories Collectible – Histories collectible is responsible for pull offing histories held with providers. Suppliers send purchase bills to head office, which, are merely paid if the stock being invoiced has really arrived at the warehouse.3. Buying – Buyers are responsible for purchasing stock for the warehouse and mercantile establishments. They monitor stock degrees in mercantile establishments, and, the warehouse, and make up one’s mind which providers to order stock from.

Buyers are besides responsible for measuring the market place and telling new stocklines when appropriate.4. Transport – The Transport map transportations stock from the warehouse to mercantile establishments.

The geographic operation of ABBC is subdivided into parts and peculiar twenty-four hours ( s ) of the hebdomad are allocated to a peculiar part.5. Financial direction – This is a senior direction map which coordinates the other maps. Particular activities include strategic planning, accounting direction, and, general determination devising.

The warehouse maintains a stock of popular merchandises. Ideally, the warehouse should ever be able to run into petitions for stock from mercantile establishments. Obtaining stock from providers should merely be necessary for keeping the warehouse ‘s stock degrees. Warehouse staffs physically organize stock harmonizing to its position, that is, warehouse-stock or stock-intransit. The former is stock which has non been allocated for transportation to any mercantile establishment, the latter is stock which has been reserved for transportation to a peculiar mercantile establishment.

The caput office notifies the warehouse of warehouse-stock which is to be stock-in-transit, and supplies the warehouse with stock transportation agendas. A transportation agenda specifies stock to be transferred to mercantile establishments on a peculiar twenty-four hours. When stock is delivered to the warehouse from providers, warehouse staff advises head office of the bringings in order for caput office forces to pay purchase bills.

Mercantile establishments are the interface between ABBC and its clients. All gross revenues made by an mercantile establishment are recorded and sent to head office for processing. Head office uses this information to update sweeping histories, and, to update its records of mercantile establishment stock lists. The latter is necessary for caput office to cipher which stock to label stock-in-transit, to find what stock must be ordered from providers, and, to fix stock transportation agendas. On occasions when mercantile establishments can non fulfill client demands for stock, the mercantile establishment generates a stock petition and sends it to head office.This rarely occurs, except for specializer merchandises which are peculiarly expensive, or, for merchandises which are in small demand.

Head office arranges to reassign the needed stock from the warehouse, if it is available, or orders the stock from a provider. There are of class extra activities which form portion of ABBC ‘s concern theoretical account, such as treating assorted disbursals, returning damaged stock to providers, scrutinizing, bad creditor direction, and so on. In this chapter, nevertheless, we have intentionally presented a simplified position of ABBC ‘s operation because otiose item would befog this instance survey.Towards the terminal of the 1990s, the direction squad of ABBC acted on advice to put in machine-controlled support for their concern by presenting a computing machine system. Some of the original system ‘s hardware remains in service today. The mainframe and minicomputers have been upgraded over the old ages, but the concern has expanded quickly whilst the implicit in engineering remains unchanged. The hardware comprises:

  • One IBM mainframe – This machine, located at caput office, shops and processes the huge bulk of ABBC ‘s informations.

  • Several IBM minicomputers – Each mercantile establishment uses a minicomputer to hive away local stock list informations, and accumulated stock petitions and gross revenues informations. In add-on, these machines manage a transcript of the warehouse stock list which they download sporadically.
  • Several character terminuss – Each mercantile establishment has a little figure of terminuss which are connected to the local minicomputer. The warehouse has a aggregation of terminuss which are connected to the mainframe remotely, via a dedicated communicating line. Head office hosts many mainframe terminuss.

  • Communicationss, pressmans and secondary storage – All minicomputers are connected to the mainframe. There is, at least 1 pressman at each site. Mainframe information is stored on discs and is archived onto tapes.

The initial system was wholly batch-oriented.

Software included, a suite of COBOL plans which manipulated structured ( Virtual Storage Access Method ( VSAM ) ) files. In kernel, information was collected, and, recorded in dealing files for subsequent batch processing. During batch processing, the dealing files were merged with maestro files. Processing was scheduled at times when the system was non in usage.

The computerized solution met outlooks of increased efficiency and decreased mistake, but it shortly became evident that its information was frequently inconsistent with world. For illustration, on reception of stock from providers, warehouse forces entered bringing inside informations into a dealing file. When scheduled, this file merged with the warehouse maestro file. During the clip between bringings and updating the maestro file, the maestro file was an inaccurate representation of the stock really held at the warehouse. Head office purchasers found themselves fall backing to written notes about expected or recent bringings.

The job of inconsistent informations was, a major lending factor to a system inspection and repair in recent old ages. The mainframe ‘s COBOL/VSAM combination was replaced with an Ads-Online/IDMS constellation. Ads-Online is a 4GL, designed chiefly for usage with the IDMS web database. Some of the COBOL plans were retained to supplement the Ads-Online solution. This revised online solution provides head office forces with up-to-date information.The system nevertheless retains a batch manner of communicating between the mainframe and minicomputers. Mercantile establishments continue to enter gross revenues informations, and stock petitions in dealing files which are batched and sent to the mainframe nightlong every on the job twenty-four hours. In add-on to the Ads-Online inspection and repair, ABBC ‘s system has evolved in a figure of other ways.

Minor alterations have been necessary to follow with altering statute law and revenue enhancement rate alterations. The IDMS information schemes have been changed to react to new merchandise types. Occasionally, adding a new merchandise caused troubles because, it is available in units non antecedently recognized by the system. One illustration involved the debut of pigment as ABBC ‘s first liquid merchandise where the system had to cover in liters.

As a effect of enlargement, caput office forces found their manual procedures for ciphering wages and rewards to be peculiarly time-consuming. Furthermore, bring forthing year-end histories and scrutinizing became a complex and erring activity. Payroll and extra accounting plans, developed in Ads-Online, were introduced in 2003.This undertaking seeks to supply a suited scenario to show the methods of developing a suited development scheme for ABBC ‘s system.

The undertaking Aims And Aims

The prevailing subject underpinning this research is:

  • Investigating an appropriate attack, and planing a proposed system to overhaul the Legacy Information System ( LIS ) of ABBC Limited.

In-order to be able to accomplish the purpose of the research, certain aims has been designed – the chief aims for this research are:1.

Review of the state-of-the-art in relation to LIS.2. Identifying the current province of the system of ABBC ltd. The jobs, issues, and challenges it faces.3. Identify the assorted engineerings available to run into the company ‘s demands.4.

Design and urge a system that will help in accomplishing improved operational efficiency and dependability.5. Propose an execution stage which will include preparation of the company ‘s squad on the new system ‘s work processes, constellation, and the different applications that were developed to attach to it.6.

Transport out a cost benefit analysis, in order to be able to convert the direction on the fiscal advantages of the new system.

Chapter Two

Literature Review


In order to supply the relevant background to the current work, attending now turns to specify, turn uping and understanding the job sphere through literature hunt. The focal point, in this manner, is to accomplish acceptable ROI ( Return on Investment ) . The job sphere in the context of this research is Legacy Information Systems ( LIS ) .

Specifying the research job therefore, involves understanding the LIS sphere, its nature and features along with how challenges related to the LIS sphere have been tackled to day of the month. A clear apprehension of assorted factors provide the necessary foundation for the current work along with placing a set of nucleus issues that is to be tackled within the undertaking.Systems development, is a term used in depicting the capableness of an bing system, in suiting alterations, both concern and proficient ( Patel 2003 ) .

The implicit in doctrine dictates that systems development does non stop, instead, a system that has been deployed with an initial capableness is evolved to go more capable and functionally richer as it emerges.While it has become apparent that administrations need to use and are using different attacks to develop and pull off their package systems ( Patel 2003 ) , presence of LIS in this regard remains an unfastened challenge ( O’Callaghan 1999 ) for bulk of concern administrations. Most LIS were developed on the traditional theoretical account of develop-and-maintain under the premise that, these systems will be used for some old ages before they are finally replaced by new and more sophisticated systems. As a consequence, the challenge is clearly reflected in seeking to accommodate big, and technically disused systems in an environment for which they were non designed for and one that is mostly emergent. Complexity is farther exacerbated by the continued proficient promotions in the field, which means more and more systems are being considered as LIS.

Legacy Information Systems – Problems

A direct effect of the inability to fit with the altering market conditions, is the major ground for, an addition in the figure of LIS that presently operate within most administrations. While it is alluring to presume that the solution to the LIS job can be had by merely throwing off these systems and, developing new systems from abrasion, the sheer volume of the figure of LIS running worldwide gives a just thought of the LIS job. ( Seacord et al. 2003 ) . The bulk of package is written utilizing old, inflexible linguistic communications like COBOL and FORTRAN.

Harmonizing to one estimation, 30 % of all bequest codification is written in COBOL, and for mainframe applications in peculiar this figure increases to around 80 % ( Seacord et al. 2003 ) . To do affairs worse, a figure of these systems are considered mission-critical and their effectual direction is, cardinal to the endurance of the organisation, ( Bennett 1995 ) .

A big bequest codification based construction means that there is a heavy economic cost with keeping these systems – in footings of attempt and money. It is forecasted that by 2020 merely tierce of all coders will be working on undertakings affecting the building of new package while the remainder will be working on sweetening and fix undertakings ( Van Deursen et Al. 1999 ) .

This underlies the fact that around 60 % -80 % of the package budget of an administration is spent on keeping and incorporating LIS with current demands ( Tilley and Smith 1995 ) . A premier illustration of the economic costs, as a consequence of LIS, is the Year 2000 job, which was estimated to hold cost administrations worldwide someplace between ?220 and ?330 billion lbs ( Miller 1997 ) .

Critical Review Of The LIS Transformation Strategies

Many schemes together with appropriate attacks have emerged to supply LIS transmutation, and, typical schemes include ( a ) renovation, ( B ) wrapper, and, ( degree Celsius ) transmutation ( both informations and, codification ) ( Brodie and Stonebraker 1995, Quilici 1995, Robertson 1997, and Aiken 1998, Aiken et Al, 1999, Bisbal et Al, 1999, Comella-Dorda et Al, 2000, Coyle, Bianchi et Al 2003 ) . There is a scope of different schemes which are normally involved with LIS transmutation in order to be able to hold an impact on the system.

While wrapping basically works with the bing system and, involves the least figure of alterations, renovation involves the most figure of alterations. Two points are of relevancy here. First the schemes are non steadfast boundaries and, as a consequence, given a practical state of affairs, different schemes can be employed ( Bisbal et al. 1999 ) . Second, care is chiefly added here for completeness intents, since it is a portion of every system development life-cycle. It is necessary to research these LIS transmutation schemes so, as to critically measure their ability to efficaciously transform LIS.


The limited feasibleness of the renovation scheme has resulted in many administrations ‘wrapping ‘ their LIS. Wraping offers an easy and cost effectual alternate compared to the renovation scheme.

Wraping plants by concealing the complexness of the system through modern looking interfaces, ( Winsberg 1995 ) . The interface sits on top of the bing plan or plan constituents of LIS and any communicating to and from the LIS are routed through the interface. In this manner the scheme removes any mismatches between the interface that exists for the peculiar LIS and, the interface required by current integrating patterns ( Shaw ; Wallnau et al.

) . When wrapped, the LIS becomes a reclaimable package constituent that allows bequest plans to be invoked from new state-of-the-art applications, thereby widening and heightening the life of bequest applications and informations. LIS can be wrapped at the functional degree, informations degree or at the user interface degree ( Comella-Dorda et al. 2000 ) .

While wrapping offers a cost effectual option to the renovation scheme, it really much remains a short-run solution and, suffers from a figure of restrictions ( Bisbal et al. 1999 ) . Wraping solves the immediate job of LIS by concealing its complexness and inability behind calendered looking interfaces or workarounds, but, in the long term wrapping adds to the complexness of the system with extra beds of package codification to pull off. Furthermore, being wholly dependent on engineering implies that the beds will go on to turn, whenever, the current engineering is replaced. Besides these issues, the scheme does non make anything to better the information issues which fundamentally remain in the same province.LIS wrapper can be applied at three different degrees of the system, the functional or logical, informations, and, user interface degree ( Comella-Dorda, S.

2000 ) . The determination shapers of the administration decide the degree where wrapper should be conducted and, more than one degree can be wrapped at the same clip ( Santiago Comella-Dorda, Kurt Wallnau, Robert C. Seacord, John Robert April 2000 ) .

User Interface Level Wrapping:

Wraping at this degree involves betterment of the seeable part of the system and, is extremely appreciated by the terminal users. One major technique used is screen trashing and it entails wrapper of the old, text-based interfaces with a new graphical interface ( Carr, David F.

1998 ) .

Data Level Wrapping:

This is the wrapper of the information of the LIS, and, it allows integrating of the bequest informations into the modern substructure and it improves connectivity. Some of the celebrated techniques used for wrapping at this degree include database gateway, XML integrating, and, informations reproduction ( R. Altman, Y. Hill, J. Klein, B. Lheureux, R.

Schulte, M. Pezzini, S. Varma 1999 ) , ( Barry, Doug July 1998 ) .


Many early LIS transmutation undertakings prescribe a complete renovation of the LIS ( Brodie and Stonebraker 1995 ) . Redevelopment, normally referred to as the Big Bang, or, the Cold Turkey Approach, is based on the statement that present LIS are old, and, slow and as a consequence should be replaced with systems utilizing modern architectures and latest engineering.

The engineering ( i.e. , package and hardware ) , together, with concern procedures and concern regulations present within the system are frequently viewed as out-of-date and, as a consequence have little or no relevancy to the administration. The scheme works by re-developing the LIS from abrasion to bring forth the mark IS. The current system remains operational until the new system is developed and, is later switched off.

Techniques are available to steer the renovation procedure. Tilley ( 1995 ) provides a LIS re-engineering scheme through a high degree model to help the renovation procedure. Other illustrations foregrounding the procedure of renovation are, the Renaissance undertaking ( Ransom et al.

1997 ) , and, the theory suggesting a set of guidelines for migration of LIS to administer environments ( Ganti and Brayman 1995 ) .While these techniques offer some counsel over how to near renovation, a complete renovation of the bing system involves a really significant hazard, for the administration ( Bisbal et al. 1999 ) . The primary issue with the renovation scheme is its focal point on re-developing the full system. In add-on, to the clip and cost required to construct the new system, it, besides requires the LIS to discontinue operation once the new system is developed and operational, which can hold serious deductions if the LIS is mission-critical ( Comella-Dorda et al. 2000 ) .

In add-on, the premise that the new system will ever be better in footings of efficiency, cost and functionality remains an unfastened inquiry for the undermentioned grounds. First, it is about impossible to suggest an full re-write of an existing IS because the premises, state of affairs, tools, and techniques are well different to the 1 that existed when the LIS was foremost developed. Second, developing the system from abrasion is frequently fraught with danger as it can take considerable sum of clip and attempt to develop. In that clip tools and techniques can go disused or, initial demands can give manner to new demands. Finally, due to miss of certification and relevant people, there remains considerable issues over whether the specifications have been captured right, or non ( Brodie and Stonebraker 1993 ) .The other restricting factor with the renovation scheme is that engineering remains the primary focal point of all the attempts and the guiding factor. The redevelopment attack is based on the premiss that, replacing the engineering is cardinal to presenting a stable system. As such, the attack suffers from chiefly offering a technology-based solution while wholly disregarding the concern factors within the bing system.

The concern cognition is either tightly coupled, or, embedded within the engineering. The primary issue with such a position is that given today ‘s state-of-the-art engineering is tomorrow ‘s bequest, administrations will go on to confront the digesting jobs associated with a chiefly proficient focal point.


LIS Migration is another of import class of system development. It is concerned with development of a mark system that can retain the functionality and, significantly, informations of the original bequest system, but, which can be easy maintained ( Mention: M. Brodie and M.

Stonebraker, Migrating Legacy Systems, Gateways, Interfaces, and, the Incremental Approach, Morgan Kaufmann 1995 ) . Migration is classified into two chief classs, system migration and, component migration. System migration is besides divided into value added, and, no value added class.

Value added migration involves alterations in the user interface, database and plan codifications of the system. Non-Value added migration involves straightforward transmutation of the LIS, besides referred to as platform emulation which is the motion of the LIS to a practical bequest machine, and, emulated on a new platform. However this attack does non work out the LIS issues but merely exchange to a newer hardware when the old hardware is no-longer supported, in add-on, this attack is non applicable to all LIS and some functionality of the LIS such as, dealing direction, might be lost during motion. Component migration is the breakage of big LIS into independent constituents that will be migrated individually.

Two schemes of component migration that will originate during the passage of the bequest system to the new platform, are, phased interoperability, and, parallel operation. Migration is similar to the re-engineering and wrapper technique but entails more complexnesss and besides exhibits greater long-run benefits ( Maseud Rahgozar, Farhad Oroumchian 2003 ) and therefore seems to be the more executable attack.Re-Engineering StrategyRe-engineering is described as a extremist, cost effectual, and, clip salvaging attack for managing the LIS quandary. It is the application of scientific, technological or proficient and concern oriented solution to the LIS challenge. Modernisation involves more prevailing alterations, conserving important part of the go outing bequest system, which, involves restructuring of of import functional sweetening, or, new package properties ( Santiago Comella-Dorda ) , ( Kurt Wallnau ) , ( Robert C. Seacord ) , ( John Robert April 2000 ) .

The chief principle of re-engineering is in two crease, the agreement of bing system to take advantage of new engineerings, and, to enable new development attempts to take advantage of recycling bing systems. Re-engineering entails change of the LIS and restructuring it to a later new and instrumental signifier which is the development of a new system, by, doing usage of some facet of the LIS ( Chikofsky, E.J. 1990 ) , ( Sneed, H.M. 1995 ) . Re-engineering can be farther bomber divided into two classs, viz.

, white box technology, which, involves the usage of contrary technology attack, and, black box technology which involves the usage of forward technology attack. The high quality of one over the other is an unfastened inquiry, as, each class entails utile advantage and depends on the LIS to be evolved ( Santiago Comella-Dorda ) , ( Kurt Wallnau ) , ( Robert C. Seacord ) , ( John Robert April 2000 ) .

Theoretical Perspective Of LIS

When an organisation efforts to alter its information system ( IS ) , it encounters jobs related to the being of a monolithic, complex, and, inflexible base of package, frequently referred to as LIS, ( Bisbal,1999 ) , which is historically embedded and therefore can non be abandoned nightlong. Somerville describes LIS as socio-technical computer-based systems that, include package, hardware, informations, and, concern procedures ( Sommerville, 2001 ) . LIS are typically slow, undependable, and, inflexible for managing new, more diverse and demanding undertakings ( Scott, 2001 ; Kelly et al.

, 1999, O’Callaghan, 1999 ) . The maps of LIS are hard to understand doing their replacing an highly ambitious undertaking. Replacing a LIS is a hazardous concern scheme for at least three grounds, ( Sommervile, 2001 ) :1. There is seldom a complete specification of the LIS, as the original certification may hold been lost.

Therefore, there is no straightforward manner of stipulating a new system, which is functionally indistinguishable to the system that is in usage.2. Business procedures, and, the ways in which LIS operate have been designed to take advantage of the package services, and, to avoid its failings. If the system is replaced, these procedures will besides hold to alter, with potentially unpredictable costs and effects.3. Important concern regulations may be embedded in the package, and, may non be documented elsewhere. Replacing the LIS may take to a loss of concern regulations, therefore lending to directors fright of alteration.

The demand to cover with LIS in an effectual manner is critical, as, a concern relies on the services provided by the LIS, and, any failure of it would earnestly act upon the daily running of such a concern. The LIS over clip, differs from the original due to external and internal factors, such as, altering Torahs, direction alterations, structural reorganisation, and redefinition of information demands. These alterations generate new or modified package demands, so the LIS is necessarily expected to besides alter. The grade of alteration is nevertheless context-specific, and, hard to implement in pattern.

The Information Infrastructure Perspective

Contemporary thought in IS research seeks to analyze design and alteration non as IS, but, as Information Infrastructures ( II ) ( Hanseth et al. , 1996 ) . Traditional IS design scheme, assumes that systems can be developed from abrasion, as stray and stand-alone applications with defined ends, start, and, stoping times as events instead than as on-going procedures ( Orlikowski 1996 ) . Such a position is limited in the present context where technological solutions seek to incorporate multiple systems across organisational and geographical boundary lines, for illustration, Enterprise Resource Planning systems ( Hanseth,2002 ) . The Information Infrastructure ( II ) position seeks to look at systems as inter-connected socio-technical webs which are more appropriate to understand, as against the challenges of presenting alteration when there are multiple LIS already in topographic point, necessitating integrating. Key features of II as outlined by Hanseth ( 2002 ) are:

  • They change over a long period of clip where the bing substructure, strongly influences how the prospective 1 can be changed.

  • Information Infrastructure is portion of big heterogenous socio-technical web, embracing worlds, technological artifacts, and, establishments.
  • It supports information sharing among a big community of different users and demands.
  • They are non defined from abrasion, but instead germinate incrementally over clip.

Hanseth ( 2002 ) further outlines some cardinal constructs that help to understand II, viz. , increasing returns, and, positive feedback, web outwardnesss, way dependence, and, lock-in and, cultivation.A classical illustration of such an attack is seen in the development of the Internet ( Abbate, 1999 ) .

The basic attack consists of altering a little portion of the substructure and do certain the freshly added parts work in consonant rhyme with the bing web. Cultivating an II implies constructing a new one such that the new characteristics besides obtain their value from the size of their installed base. The II position emphasizes the demand to esteem history of bing systems and their interconnectednesss in the design and execution of alteration. The LIS position elaborates on the features of these bing systems and therefore provides penetrations into how they should be considered in planing new IIs.

These theoretical thoughts are drawn upon to analyse an on-going undertaking to present a system ascent in ABBC Ltd, a context characterized by multiple LIS.

Background Of The Case Study

The procedure of replacing a LIS normally involves a scheme wherein the assorted attacks are combined in changing grades. Sommerville ( 2001 ) suggests that the scheme to germinate a LIS should be based on the consequences of the system quality and concern value appraisal. Low quality and low concern value LIS should be scrapped. Low-quality and high-business value LIS make an of import concern part but are expensive to keep, and so should be re-engineered or replaced if a suited system is available. High-quality and low-business value LIS should be replaced scrapped wholly or maintained while high-quality and high concern value must be kept in operation utilizing normal system care.Every section and subsystem in the company can be viewed fundamentally as an information-processing bureau.

Management can actively utilize this information for monitoring and commanding the quality of service, track how some of the company ‘s resources are used, and, in garnering information for both short-run and long-run determination.The really few stand entirely computing machines do non assist in bring forthing elaborate concern public presentation studies. Present observation reveals that current systems requires an upgrade to run into the concern demands in the countries of stock-control, accounting and audits as the system is slow that it takes longer clip and hold for mistakes to be corrected.As of now each section in each subdivision are managing client issues on an ad-hoc mode, utilizing a assortment of tools.

A individual procedure and solution is required to enable a consistent procedure for the gaining control, declaration and bringing procedure for both employees and clients to forestall harm to the company ‘s nucleus concern.Much clip is spent on simple undertakings such as day-to-day informations rapprochements due to the slow end product of the current system, and besides due to the fact that it has non been designed to back up so many concurrent users per case.

The ABBC Ltd ( UK ) Challenge

In implementing system upgrades an issue of concern is the bing bequest information systems ( LIS ) , which are old and locked, missing beginning codification and certification, and be given to be stored in assorted proprietary formats, doing sharing informations between different systems hard. Schemes to turn to these LIS demand to be earnestly considered, whilst designing and implementing the new system. In ABBC Ltd, assorted restraints have been identified through the observation of the present province of personal businesss ; amongst them is the presence of multiple LIS and the related absence of a incorporate information and communicating substructure.

As a consequence, the bing systems are unable to supply directors with information on indispensable indexs which would cross-link different resources with activities, such as associating to different sections viz. , histories, stock-control and audit.The available literature on LIS recommends schemes based on the premise of stray systems. A long term observation was done to obtain an overview of the system including its function, linkages with other bing systems, information flows, and functionality. As mentioned earlier on, the system ( SIS2 Prog ) consists of multiple, analogue and disconnected systems stand foring the demands of different units and sections. This multiplicity is reflected in different technological solutions stand foring a complex and disparate installed base including applications built on MS-DOS and MS-Windows runing systems, utilizing DBASE, Visual Basic, Access, Excel, and Lotus Notes. As a consequence of this multiplicity of different technological solutions that are developed by different IT houses, the SIS2 Prog in entirety deficiencies uniformity, compatibility, and is incapable of pass oning and sharing information between plans.

SIS2 Prog is the first computing machine system of the company developed and deployed at the different subdivisions in 1999-2002. The system was developed on “dBase III” relational database direction system on Microsoft DOS. This system did non back up a mouse. It can run in a MSDOS window in Win95, but non on Win98. The jobs of the system are compounded by the design of the manual system in which information is compiled.As a consequence, there is non-uniformity and ambiguity in the concern regulations, doing comparings and integrating across installations and clip hard. Problems in the usage of the SIS2 Prog were besides worsened by the limited computing machine accomplishments of the employees. As a consequence, they did non hold the capacity to cover with the already inflexible design of the system.

The absence of the beginning codification and relevant certification besides created jobs in adequately keeping the bing system. The effects of the proficient restrictions of SIS2 Prog are summarized below:1. Lack of portability across different computing machines:Despite the purchase of new Personal computers, the company could non port SIS2 Prog to this new hardware because they did non hold the installing files.

2. Long get down up clip:It takes long clip to carry through undertakings that could hold been performed in short clip with powerful computing machines. For illustration, it takes up to 8 proceedingss for a computing machine to get down.3. Problems of printing and transportation of files:If users want to include accounting informations in their studies in word processors, they have to publish the information, and so re-type them on their studies because the computing machines are non able to copy-paste big sum of informations. In add-on, if they want to reassign the information to another computing machine they have to utilize phonograph record or USB sticks regardless the size of the files.4. Incompatibility across plans:To bring forth a customised graph of the stock control informations for case, users need to publish the informations and retype them in spreadsheet package like Microsoft Excel since the SIS2 Prog generated graphs can non be copied to word processor plans because they are generated in MS DOS plan.

Chapter 3 – Research Methodology ( Qualitative And Quantitative )


This chapter is a sum-up of the processs used in carry oning the research. It involves the methods and processs which handles the mode in which the informations were collected and analyzed. It besides illustrates the mode in which qualitative and quantitative information are presented.

Qualitative And Quantitative Research Methods

Quantitative research can be defined as an enquiry into an identified job, based on proving a theory, measured with Numberss, and which can be analyzed utilizing statistical techniques. The end of this type of research method is to find whether the prognostic generalisations of a theory holds true.

By contrast, a research based on qualitative procedure of enquiry has the end of understanding a societal or human job from assorted positions. Qualitative research is normally conducted in a natural scene and involves a procedure of constructing a complex and holistic image of the subject or country of involvement. The choice of the appropriate research method to be used in a given survey is based upon the job of involvement, resources available, the accomplishments and preparation of the research worker, and the audience for the research. It must be noted that some types of research may integrate both quantitative and qualitative methodological analysiss. However there are important differences in the premises underlying these attacks, every bit good as in the informations aggregation and analysis processs used ( Mason, 1996 ) , ( Kernighan 1976 ) .It is of import to place and understand the research attack underlying the survey because the choice of a research attack normally influences the types of inquiries asked, the methods selected, the statistical analyses used, what decisions are made, in order to carry through the ultimate end of the research. When reexamining scientific research, the inquiries asked, and the replies given, will change based on whether the research method used is quantitative or qualitative.

Types Of Qualitative And Quantitative Research Approach

Three common types of quantitative research methods ( Mason, 1996 ) are:1. Experimental – Real experiments are characterized by the random assignment of topics to experimental conditions, and, the usage of experimental controls.2. Semi-Experimental – these types of surveies portion about all of the characteristics of experimental designs except that they involve non-random assignment of topics to experimental conditions.3.

Surveys – These include cross-sectional and longitudinal surveies utilizing questionnaires or interviews for informations aggregation intents with the purpose of gauging the features of a big population of involvement, based on smaller samples from that population.Three common types of qualitative methods ( Mason, 1996 ) are:1. Case Studies – In a instance study the research worker explores a individual entity or phenomenon – the instance, bounded by clip and activity ( e.

g. , a plan, event, establishment, or societal group ) , and collects elaborate information through a assortment of informations aggregation processs over a fit period of clip. The instance survey is a descriptive record of an person ‘s experiences and/or behaviours kept by an outside perceiver.2. Ethnographic Studies – In this type of research the research worker surveies an integral cultural group in a natural scene over a specific period of clip. A cultural group can be any group of persons who portion a common societal experience, location, or other societal features of involvement.3.

Phenomenological Studies – This involves the procedure in which human experiences are examined through the elaborate description of the people being studied – the end is to understand the lived experience of the persons being studied. This attack involves researching a little group of people intensively over a long period of clip.The method selected for this undertaking is instance survey and the modernisation of a Legacy system is the instance under probe. The scheme adopted for aggregation of information for the qualitative survey was through the observation and reviewing of the jobs and issues faced by the company in the usage of the current system and happening a suited option for them. Case surveies are so designed to convey out the inside informations from the point of view of the participants by utilizing multiple beginnings of informations.

Data Collection

Datas for the qualitative survey were collected chiefly through observation.

I had already identified specific facets of the old system to be addressed. Saunders et Al ( 2003 ) opined that in order reply some equivocal research inquiries to run into the aims of the undertaking research it is extremely imperative that new primary informations be collated by the research worker and re-analysed every bit much as possible the old informations ( secondary beginning ) collated for other intents.

Datas Analysis

Analysis of informations in a research undertaking involves sum uping the mass of informations collected and showing the consequences in a manner that communicates the most of import characteristics. In quantitative research analysis involves things like the frequences of variables, differences between variables, and, statistical trials designed to gauge the significance of the consequences and the chance that they did non occur by opportunity. This is done fundamentally by numbering how frequently something appears in the informations and comparing one measuring as against others. At the terminal of the analysis, non merely do we hold a mass of consequences but we besides have what we might name a large image, that is, the major findings. In qualitative research the involvement is non merely in detecting the large image but the usage of different techniques to happen it.

As in quantitative research, there may be some informations which are mensurable but for the most portion we are interesting in utilizing the information to depict a phenomenon, to joint what it means, and to understand it. The basic procedure of analysing quantitative and qualitative information is the same. We start by labeling every piece of information so that the differences and similarities between them can be easy recognised.


References/ List Of Books And Articles Read That ‘s Helping With The Undertaking.

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Largo, ‘Methods and Tools for Data Value Re-Engineering ‘ , Proceedings International Conference on Applications of Databases. Lecture Notes in Computer Science 819, Springer-Verlag 1994, pp. 499-411.D.

Aebi, ‘Data Re-engineering – A Case Study ‘ , Proceedings 1st East-European Symposium on Progresss in Databases and Information Systems ( ADBIS’97 ) , September 1997, Springer-VerlagBachmann, ‘A CASE for Reverse Engineering ‘ , Datamation, July 1988, pp. 49-56C. Batini, M. Lenzerini, S. B. Navathe, ‘A comparative analysis of methodological analysiss for database scheme integrating ‘ , ACM Computing Surveys, 18 ( 4 ) , December 1986, pp. 323-364K. Bennett, ‘Legacy Systems: Coping with Success ‘ , IEEE Software, 12 ( 1 ) , Jan 1995, pp.

19-23Bennett, K. ‘’Legacy Systems ” , IEEE Software, January 2002, pp 60-73E. J. Chikofsty and J. H.Cross II, ‘Reverse Engineering and Design Recovery: A Taxonomy ‘ , IEEE Software, 7 ( 1 ) , January 1990, pp.

13-17D. N. Chin, A. Quilici, ‘DECODE: A Co-operative Program Understanding Environment ‘ , Journal of Software Maintenance, 8 ( 1 ) , 1996, pp.

3-34G. Dedene, J. De Vreese, ‘Realities of Off-Shore Reengineering ‘ , IEEE Software, 12 ( 1 ) , Jan 1995, pp.

35-45J. Fong, ‘Converting Relational to Object-Oriented Databases ‘ , SIGMOD Record, 26 ( 1 ) , March 1997, pp. 53-64I. Graham, ‘Migrating to Object Technology ‘ , Addison-Wesley, 1994, pp. 45-55J-L. Hainaut, J.

Henrard, J-M. Hick, D. Roland, V. Englebert, ‘Database Design Recovery ‘ , Proceedings 8th Conference on Advanced Information Systems Engineering ( CAiSE’96 ) , May 1996, pp. 272-300R.

Orfali, D. Harkey, J. Edwards. ‘The Essential Distributed Objects Survival Guide ‘ , John Wiley and Sons, 1996. Ovum Ltd. , ‘Ovum evaluates. Software proving tools ‘ , London: Ovum Ltd 1996.ESPRIT Project – Lancaster University, ‘RENAISSANCE Project – Methods & A ; Tools for the development and reengineering of bequest systems ‘ ,Santiago Comella-Dorda, Kurt Wallnau, Robert C.

Seacord, John Robert A Survey of Legacy System Modernization Approaches – April 2000R. Richardson, D. O’Sullivan, B. Wu, J. Grimson, D. Lawless, J.

Bisbal, ‘Application of Case Based Reasoning to Legacy Systems Migration ‘ , Proceedings fifth German Workshop on Case-Based Reasoning – Foundations, Systems, and Applications, March 1997, pp. 225-234P. Winsberg, ‘Legacy Code: Do n’t Bag it, Wrap it ‘ , Datamation, 41 ( 9 ) , May 1995, pp.

36-41Sneed, H.M. , ‘’Enscapulating Legacy Software for Use in Client/Server Systems ” working conference paper. IEEE Computer Society Press, 2001 pp 104-119Tillery, S.R, Smith, D.B, ‘’Perspectives on Legacy system Re-engineering package.

Eng.Inst.Carnegie Mellon, Univ.Pittsburg 1996, pp 30-41Wilson, David A. , ‘’Managing Information ” 2nd edition, 2001. Pp 127-148.


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